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This paper proposes a piezoelectric energy harvester that concentrates force on the piezoelectric element by parallel springs. When vibrating, the force exerted by the mass is released at three equal points on the surface of the brass substrate through three parallel springs. This concentrated release of energy through the spring amplification effect facilitates large deformation of the piezoelectric ceramic sheet, resulting in a higher charge output. The results show that under the combined action of a 14 g annular hollow mass and a 0.3 mm wire diameter stainless steel spring, the energy harvester based on the lead zirconate titanate ceramic exhibited an outstanding output power of 1.0–32.1 mW at a low resonance frequency with acceleration amplitudes of 0.5–3 g (1 g = 9.8 m/s2). More importantly, to match the vibration frequency of the actual environment, this paper optimized the structure of the harvester and proposed that the harvester can be designed by selecting the weight of the mass block, the parameters and number of springs, and the shape of the brass substrate. The energy harvester designed in this study is expected to capture energy from low-frequency natural environments and exhibit outstanding output performance, which can provide guidelines for future efforts in this direction. [ABSTRACT FROM AUTHOR]

Active thermography using pulsed heating is a fast and reliable method for detecting flaws in composite and metallic materials. This paper analyzes the temperature decay that occurs immediately after flash heating the front surface of stainless steel specimens as a function of time, based on a novel application of the equivalent circuit approach (ECA). The temperature decay from the front surface is equated to the discharge of a capacitor. The ECA is based on the charging (temperature rise due to flash heating) of a capacitor, followed by its discharge (temperature decay) through a series of resistors (which depends on the conductivity of the material) and capacitance (which depends on the thermal capacitance of the layers) through which the heat is dissipated. The proposed approach analyzes the sequences of temperature data obtained at each pixel location during cooling from a step wedge and a specimen with multiple flat-bottom holes. Time constant maps derived from the analysis are used to ascertain the thickness of the step wedge, detect the flaws, and evaluate the remnant thickness of the flaws. A correlation has been established between the thickness and the time constants. The above approach has been used to estimate the diameter of the flat-bottom holes. [ABSTRACT FROM AUTHOR]

Additive manufacturing has the potential to repair damaged parts, but the performance of additive materials under high strain rate loading is still uncertain—especially with the added complexity of an interface with an existing wrought material. In this work, 304L stainless steel samples were intentionally damaged and then repaired with wire-fed laser additive manufacturing. The samples were subjected to shock loading to generate incipient spall. Velocimetry and post-mortem metallography results show that when the additive repair process parameters are optimized to reduce porosity and match the equation of state of the original material, the influence of the repair region on the shock propagation is negligible. The free-surface velocity profile and internal damage morphology of the repaired sample are shown to be practically identical to the pristine material. [ABSTRACT FROM AUTHOR]

Properties of fragmentation from an explosively driven 316L stainless steel spherical shell section fabricated by a laser powder bed additive manufacturing process with minimal surface finishing are investigated. This shell is driven by an insensitive high explosive, resulting in high strain rate deformation (>8 × 103 s−1) and failure of the stainless steel. Photonic Doppler velocimetry measures the expansion rate; dynamic radiography and high-speed imaging capture the fracture behavior of the stainless steel. The fracture response of the additively manufactured stainless steel shell is compared to published experimental results on additively manufactured 316L stainless steel and conventionally manufactured wrought 316L and 304 stainless steel shell fragmentation. Despite preferred crack orientation, suggesting the influence of surface grooves on fracture time, fragment size is identical to that measured in a similar experiment on wrought 304 stainless steel. Further analysis indicates that the 316L additively manufactured stainless steel shell exhibits comparable spall strength and fragmentation toughness to conventionally manufactured stainless steel yet lower failure strain due to surface stress concentrations. [ABSTRACT FROM AUTHOR]

We present a systematic study of Hugoniot properties of porous 316L stainless steel using both a simple interpolation scheme and direct shock simulations in order to probe pore collapse kinetics as well as final thermodynamic states. Both methods indicate that equilibrated Hugoniot properties depend on pore density only and not on the pore distribution or size. We then create a simple porous equation of state model that is shown to be accurate for a range of validation data. This allows us to extend our simulations to make direct comparison to experimental data that have generally significantly larger system sizes and durations. In addition, our direct shock simulations indicate that the relaxation time after hotspot formation is system size dependent and can reach nanosecond timescales for the largest pores investigated in our study, thereby possibly having a measurable effect on fast dynamic loading experiments [ABSTRACT FROM AUTHOR]

This work presents first experiments toward the development of continuously renewable (extrudable) pebble-based carbon rods for use as plasma-facing components in extreme steady-state plasma flux environments. The primary envisioned application of this work is a first wall that can survive long-term in future magnetic fusion power reactors while also improving recovery of the reactor fuel (tritium and deuterium atoms). Bench tests applying extreme steady-state front-surface heat loads of up to 50 MW/m2 are presented. Continuous pebble rod front-surface recession and intact pebble recovery are successfully demonstrated, at a rate of order 0.2 cm/s. Numerical simulations of the pebble rod front-surface recession are able to match observations reasonably well, indicating that the recession mechanism can be understood as occurring due to pebble thermal expansion and resulting shock and cracking of the inter-pebble binder. Tests of the pebble rod extrusion demonstrate that friction between the rods and the stainless steel extrusion channel is tolerably low (<50 N for the expected channel length) over a wide range of temperatures. Front-surface outgassing rates below 1000 Torr L/s/m2 are achieved, believed to be sufficiently low for use in magnetic fusion reactors. Initial parametric scans over pebble rod size and binder fraction to vary front-surface recession rates are presented. [ABSTRACT FROM AUTHOR]

This paper reports on spall failure and damage modes in Laser Powder Bed Fusion fabricated Stainless Steel 316L (SS316L) with intentional levels of low-volume (1–5 vol. %) porosity and pore sizes of 200, 350, and 500 μm. The fabricated specimens were subjected to uniaxial-strain plate-impact loading at ∼4.5 GPa, to initiate incipient spall failure. Analysis of velocimetry profiles measured using multi-probe photon-Doppler velocimetry coupled with post-mortem analysis of soft-recovered samples reveals local suppression of spall failure (termed as spall-dominated) as a function of porosity, as the failure mechanism transitions from spall-centered tensile stress dominated to a pore-centered microstructure-dominated damage mode involving void/crack nucleation and growth at pre-existing pores. The critical porosity level where the suppression of spall failure is first observed, as well as the spall location, is dependent on both the volume fraction and the size of the initially fabricated pores. In samples of 500 μm pore size, the suppression of spall failure is observed with as little as 1 vol. % porosity, while samples with smaller pores (200 μm) still experience spall-centered tensile stress dominated failure with higher levels (5 vol. %) of porosity. In the case of pore-centered microstructure-dominated failure, spall damage can occur but the spall plane is shifted toward the rear free surface, or more generally in areas further away from the region with pores. Highly heterogeneous deformation twinning, shear banding, grain rotation, and cracking are observed in the vicinity of pre-existing pores and expected spall failure sites. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) is a cathodic reaction of water splitting which is crucial in energy conversion. However, its wide-scale industrial applicability is limited by the slow reaction kinetics and complex diffusion of generated gas bubbles. In this study, we chose the readily available, low-cost stainless steel as a conductive substrate and feasibly in-situ developed the active phase ZnIn 2 S 4 and Ni-doped ZnIn 2 S 4 on it as a high-rate cathode for HER in acidic, alkaline, and neutral conditions. The Ni-doped electrocatalysts, when compared to bare ZnIn 2 S 4 , have higher electrocatalytic activity for HER, with low overpotentials of only 259 mV and 224 mV, to generate a high current density of 100 mA cm−2 in 0.5 M H 2 SO 4 and 1 M KOH, respectively, exhibiting obviously enhanced performance. The presence of Ni atoms is evident in EDS mapping, TEM analysis, and ICP technique. A detailed analysis of the electrochemical characteristics of the generated electrocatalysts was carried out to gain a better understanding of the effect of additional doping atoms. We not only demonstrate a feasible method for developing unique, stable and efficient HER electrocatalysts in all pH settings by comprehending the collaborative effect of the active phase, doped Ni atoms, and affordable stainless-steel substrate, but also point out new avenue to branch out self-standing HER electrocatalyst categories. • An appropriate large-scale industrial production method. • A simple and universal strategy for increasing HER activity. • Competitive overpotentials in a wide pH range. [ABSTRACT FROM AUTHOR]

Benzoylurea (BU) insecticides have been widely used for pest control as third-generation insecticides. Considering that their residues in food may cause adverse effects on human health, the upper limits of BUs remaining in food have been set by the administration. Therefore, it is essential to develop a sensitive and efficient analytical method to determine the residues of BUs in food. Stir bar sorptive extraction (SBSE) is a novel sample preparation technique, and stainless steel wire (SSW) is an ideal substrate for an SBSE device. In this work, a novel SBSE device of SSW jacket-free stir bar with a dumbbell shape was designed and prepared. The conjugated microporous polymer CMP-F6, which possesses a porous structure, high hydrophobicity and rich fluorine-containing functional groups, was immobilized on the surface of SSW by the method of polyacrylonitrile glue adhesion. Compared with previous studies, which used SSW as a substrate, the method of etching partial SSW with hydrochloric acid, on the one hand, made the surface of SSW rough and easy to modify the extraction coating, and on the other hand, converted itself into a dumbbell-shaped structure, which is conducive to improving the extraction efficiency and stability of the SBSE device. The method of SBSE-HPLC-UV was established for determining five BUs. Owing to the hydrophobic interaction and F–F interaction between CMP-F6 and analytes, this method showed good extraction efficiency and had good linearity (R2 ≥ 0.9945) and high sensitivity (LODs in the range of 0.1–0.2 ng mL−1). It was used for the analysis of benzoylurea in an apple juice sample, and the recoveries were 74.3–117.9%. [ABSTRACT FROM AUTHOR]

Metal-supported solid oxide fuel cell (MS-SOFC) has been attracting increasing attention due to relatively low materials cost and robust mechanic strength particularly for mobile applications. However, long term stability has been an issue for its application. It is challenging to isolate the degradation behavior and predict maximum lifetime of the metal substrate when assembled as full cell since many parameters may affect cell performance and life expectancy. We systematically investigated and reported the long-term oxidation behavior of porous stainless steel 430 L for up to 1500 h at 800°C under dry and 3 vol% H 2 O humidified H 2 /Ar mixture (10 vol% H 2) atmosphere to simulate its applications in MS-SOFC. Our results show that the surface oxide scale of the porous 430Lsubstrate in both atmospheres are dominated by Cr 2 O 3 and small amounts of MnCr 2 O 4 or FeCr 2 O 4 spinel oxides depending on the gas conditions, where the oxidation process could be divided into three stages with distinct characteristics. Stepwise surface color change, morphology and thickness of the formed oxide scale, elemental migration and distribution along the bulk alloy/oxide scale interface, and oxidation kinetics as a function of exposure time are systematically and thoroughly studied at high resolution. Based on the measured weight gains and thicknesses, oxidation kinetic parameters are extracted. These kinetic parameters are not only valuable for understanding the oxidation rate of porous 430 L in high temperature applications such as in MS-SOFC, but also can be used to predict the life expectancy of 430 L supported SOFC device which is critical for real and long-term applications. • Oxidative studies are performed simulated SOFC anode conditions for 1500 h. • The oxidation kinetics reflect three stages of oxidation characteristics. • Oxides are mainly composed of Cr 2 O 3 and did not undergo breakaway oxidation. • The estimated life of porous 430 L by oxidation kinetics is about 10,000 h. • Oxidation rate is as low as 2.33 × 10−4 %2 h−1 under ppm level of oxygen partial pressure. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical studies on the local stability and compression resistances of laser-welded stainless-steel T-section stub columns. A testing program was first conducted, including material coupon tests, residual stress measurements, and 20 stub column tests. The testing program was supplemented by a numerical modeling program, in which finite-element models were developed and validated against the test results. The finite-element models were afterward used to perform parametric studies to obtain additional numerical data. The test and numerical data were adopted to evaluate the main design rules in the American and European standards and the continuous strength method. The evaluation results indicate that the American and European standards yield conservative resistance predictions, especially for nonslender T-sections, owing to no consideration of material strain hardening, while the continuous strength method is shown to provide greatly improved design accuracy and consistency over the American and European standards. [ABSTRACT FROM AUTHOR]

Unlike polymers, glass is prone to fracturing under localized stress during roll embossing. Molds traditionally used for glass embossing are rigid and unsuitable for roll embossing. In this investigation, we utilized a modified soft polydimethylsiloxane (PDMS) mold, known for its ease of fabrication and superior replication capacity, for roller embossing on glass. This innovation significantly cuts mold expenses while preserving PDMS's hydrophobic and low surface energy attributes. Consequently, it prevents adhesion between the glass and the mold during high-temperature embossing, ensuring that the demolding process does not harm the glass surface. We successfully carried out roll embossing on optical glass with a mere 1.65 mm thickness, using a self-devised stainless steel carrier plate and a mobile induction heating apparatus. This heating methodology departs from the conventional practice of employing multiple heat sources in glass embossing and instead uses a singular heat source. Induction heating is applied directly to the mold and 420 stainless steel carrier. The optical glass surface reaches a remarkably uniform temperature, with a minimal temperature differential of only 2.5 °C, which is highly advantageous for mobile roller embossing, resulting in a high replication rate of V-groove microstructures on glass. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to explore the influence of corrosion-deformation interactions (CDI) on the corrosion behavior and mechanisms of 316LN under applied tensile stresses. Design/methodology/approach: Corrosion of metals would be aggravated by CDI under applied stress. Notably, the presence of nitrogen in 316LN austenitic stainless steel (SS) would enhance the corrosion resistance compared to the nitrogen-absent 316L SS. To clarify the CDI behaviors, electrochemical corrosion experiments were performed on 316LN specimens under different applied stress levels. Complementary analyses, including three-dimensional morphological examinations by KH-7700 digital microscope and scanning electron microscopy coupled with energy dispersive spectroscopy, were conducted to investigate the macroscopic and microscopic corrosion morphology and to characterize the composition of corrosion products within pits. Furthermore, ion chromatography was used to analyze the solution composition variations after immersion corrosion tests of 316LN in a 6 wt.% FeCl3 solution compared to original FeCl3 solution. Electrochemical experiment results revealed the linear decrease in free corrosion potential with increasing applied stress. Electrochemical impedance spectroscopy results indicated that high tensile stress level damaged the integrity of passivation film, as evidenced by the remarkable reduction in electrochemical impedance. Ion chromatography analyses proved the concentrations increase of NO3− and NH4+ ion concentrations in the corrosion media after corrosion tests. Findings: The enhanced corrosion resistance of 316LN SS is attributable to the presence of nitrogen. Research limitations/implications: The scope of this study is confined to the influence of tensile stress on the electrochemical corrosion of 316LN at ambient temperatures; it does not encompass the potential effects of elevated temperatures or compressive stress. Practical implications: The resistance to stress electrochemical corrosion in SS may be enhanced through nitrogen alloying. Originality/value: This paper presents a systematic investigation into the stress electrochemical corrosion of 316LN, marking the inaugural study of its impact on corrosion behaviors and underlying mechanisms. [ABSTRACT FROM AUTHOR]

In this study, a Finite Element Computational (FEC) model for automotive bellows exhaust pipes is established, and the impact of displacement loads on their fatigue life is investigated. The relationships between various structural parameters of the exhaust pipes and stress, strain, and cycle counts are elucidated. Furthermore, the bellows' structure is optimized through an orthogonal experiment. A microscopic morphological analysis is conducted on 309S stainless steel automotive bellows exhaust pipes after fatigue failure. The findings indicate that as displacement loads increase, the fatigue life of the bellows exhaust pipes decreases. The error between finite element analysis and experimental results is found to be less than 8,8 %. During the water swell forming stage, partial martensite is produced due to cold deformation. Under alternating loads, with noticeable cracks at the wave peaks, indicating the presence of internal fatigue characteristics. [ABSTRACT FROM AUTHOR]

In order to improve the quality of people 's travel and improve the performance of travel insulation cup, the thermal deformation behavior of 304 stainless steel, the edible grade material of travel insulation cup, was studied by Gleeble-3800 thermal / mechanical simulation machine. The true stress-strain curve of 304 stainless steel was obtained by hot compression test with deformation temperature of 800~1 100 °C and strain rate range of 0,001 ~ 1 s-1. According to the real stress-strain curve, the Arrhenius constitutive model of 304 stainless steel was constructed. The results show that the flow stress of 304 stainless steel increases with the increase of deformation temperature and strain rate. The theoretical stress value predicted by the constitutive model is fitted with the experimental results, and the correlation is 0,995, indicating that the model has high prediction accuracy. [ABSTRACT FROM AUTHOR]

This study investigates the impact of combined texturing by micromachining and chemical functionalization on the wetting behavior and water condensation on stainless steel 304. The transition from Wenzel to Cassie-Baxter or impregnated Cassie-Baxter regimes is investigated. Understanding this transition is critical for advancing surface engineering, as it enables precise control over wetting behavior for various applications. Herein, we report on the wire EDM (wEDM) machining on stainless steel 304 to produce two distinct microstructure patterns with directional canals or pyramidal structure, and their performance in water condensation. These patterns significantly impact water condensation performance. wEDM is employed to create surface roughness, followed by phosphoric acid treatment and chemical functionalization with trichloro-1H,1H,2H,2H-perfluorooctyl silane. Contact angle measurements reveal a synergistic effect between groove direction and silane coating, leading to hydrophobic surfaces and dropwise water condensation. Specimens with directional canals exhibit a contact angle of 150°, while specimens with pyramidal structures exhibit 151o. Roll-off angle experiments showcased distinct behavior among specimens featuring canals or pyramidal structures. Specimens with canals exhibit notably lower roll-off angles compared to both flat surfaces and those with pyramidal patterns, leading to a dependence of roll-off angles on the orientation of canals. In humid environments, micromachined specimens exhibit superior water condensation capability compared to untreated SS304 surfaces. Chemically functionalized grooved specimens present larger condensate droplet diameters than flat surfaces. An enhancement in water condensation and a sevenfold higher latent heat transfer coefficient is reported. Specimens with chemical functionalization achieve corrosion protection with an efficiency reaching 82.9%. [ABSTRACT FROM AUTHOR]

An attempt has been made to fabricate electroless duplex (Ni-P-ZnO/Ni-P-SiC) coatings on the mild steel materials. Present investigation focused on ZnO and SiC nanoparticles concentration on the corrosion resistance and microhardness of duplex coating. Coated substrates are characterised by using the X-ray diffraction analyses to know the structure of deposit. Surface morphology and element composition was evaluated by means of scanning electron microscope (SEM) attached with the energy dispersive spectrometer (EDX). Coating was heat treated for 1 hour at 400°C temperature. Microhardness of the coatings was examined by using Vickers microhardness tester. Corrosion parameters of the duplex coating were evaluated by performing the potentiodynamic polarisation studies in 3.5% NaCl solution. Experimental observations confirm that Ni-P-SiC outer layered coating offers maximum microhardness and duplex coating with Ni-P-ZnO as external layer provides maximum corrosion protection. Maximum load bearing ability of SiC nanoparticles offers superior microhardness to the Ni-P-SiC external layer coatings. Higher electrochemical resistive ZnO nanoparticles provide good corrosion protection to the Ni-P-ZnO external layer coatings. Formation of intermetallic compounds after heat treatment process enhances the both the coatings microhardness and resistance to corrosion. [ABSTRACT FROM AUTHOR]

Surgical stabilization of rib fractures (SSRF) using standard rib plating systems has become a norm in developed countries. However, the procedure has not garnered much interest in low–middle-income countries, primarily because of the cost. This was a single-center pilot randomized trial. Patients with severe rib fractures were randomized into two groups: SSRF and nonoperative management. SSRF arm patients underwent surgical fixation in addition to the tenets of nonoperative management. Low-cost materials like stainless steel wires and braided polyester sutures were used for fracture fixation. The primary outcome was to assess the duration of hospital stay. Twenty-two patients were randomized, 11 in each arm. Per-protocol analysis showed that the SSRF arm had significantly reduced duration of hospital stay (22.6 ± 19.1 d versus 7.9 ± 5.7 d, P value 0.031), serial pain scores at 48 h and 5 d (median score 5, IQR (3-6) versus median score 7, IQR (6.5-8), P value 0.004 at 48 h and median score 2 IQR (2-3) versus median score 7 IQR (4.5-7) P value 0.0005 at 5 d), significantly reduced need for injectable opioids (9.9 ± 3.8 mg versus 4.4 ± 3.4 mg, P value 0.003) and significantly more ventilator-free days (19.9 ± 8.7 d versus 26.4 ± 3.2 d, P value 0.04). There were no statistically significant differences in the total duration of ICU stay (median number of days 2, IQR 1-4.5 versus median number of days 7, IQR 1-14, P value 0.958), need for tracheostomy (36.4% versus 0%, P value 0.155), and pulmonary and pleural complications. SSRF with low-cost materials may provide benefits similar to standard rib plating systems and can be used safely in resource-poor settings. [ABSTRACT FROM AUTHOR]

Additive and subtractive (Add/Sub) manufacturing processes are increasingly being combined to produce complex parts with unique geometries and properties. However, the design of such combined processes is often challenging as it requires a deep understanding of the interaction between the different processes. On the other hand, digital twin (DT) technology has become a powerful tool in recent years for optimizing manufacturing processes. This article explores the use of the digital twin technology for a holistic process planning of combined additive and subtractive processes. The article describes the integration of laser metal deposition (LMD) and micro-milling prediction models of resulting geometry (width and height), hardness, and surface roughness into the digital twin. This is then used for combined process planning to achieve different target values regarding resulting geometry and surface roughness. For the planning of this combined process chain, further criteria such as tool life, energy, and process time are considered in the optimization, showing the potential for sustainable and efficient production. Sensorless cutting force estimation is also used to detect small cutting forces, with the potential to use this as a soft sensor for roughness estimation. The measured width, height, and roughness as a result of the process parameters suggested by the optimization algorithms showed a mean absolute percentage error (MAPE) of 4, 17, and 16%, respectively. [ABSTRACT FROM AUTHOR]

This study investigates the structure–property relationship in a dissimilar joint between super duplex stainless steel (sDSS 2507) and pipeline steel (X-70) using gas tungsten arc welding and ER2594 filler. Tubing and risers used to transport hydrocarbons are regularly joined using these dissimilar metals. The microstructures of lower heat input (LHI-0.7 kJ/mm) and higher heat input (HHI-1.4 kJ/mm) weldments were examined to understand the influence of heat input on the structure–property relationship. The weldments' mechanical characteristics were tested via hardness, impact, and tensile tests. Base metal and weld zone/interface characterization were studied utilizing optical and scanning electron microscopes with energy-dispersive spectroscopy (EDS). Elemental variation was confirmed by EDS spectra, elemental line mapping, and electron probe microanalysis with wavelength-dispersive spectrometer along the weld interface and weld zone. Significant microstructure variation was observed in X-70 BM at the LHI and HHI weld interfaces. Type II boundary and macro-segregation forms like peninsulas and islands were present in both weldments. In LHI and HHI weldment, duplex microstructure dominates the weld zone cap and filler pass. In the backing pass, duplex microstructure replaces skeletal ferrite, which predominates in the root pass of the HHI weld zone. LHI weldment has an average microhardness of 275 ± 7 HV0.5, while HHI had 285 ± 5 HV0.5. Both weldment's tensile tests revealed that the sample fractured on the weaker X70 BM side. LHI and HHI weldments had 600 MPa and 610 MPa ultimate tensile strengths and 22% and 18% elongation percentages, respectively. LHI weldments (200 ± 7 J, 210 ± 4 J) and HHI weldments (210 ± 5 J, 220 ± 8 J) have lower average impact toughness in cap and root pass than the sDSS 2507 BM (320 ± 3 J) and X-70 BM (300 ± 6 J), respectively. The increase in heat input led to a minimal 2% difference in tensile strength, a notable 10% increase in hardness, and a slight 5% variation in impact toughness between LHI and HHI weldments. Marine and offshore applications may benefit from investigating the sDSS 2507/X-70 DWJ's process parameter selection, thermodynamic analysis, and structure–property relationship. [ABSTRACT FROM AUTHOR]

This paper utilizes the plasma arc as the heat source to successfully fabricate well-formed thin-walled parts using combined cable wire duplex stainless steel 2209. Microstructure of parts exhibited the favorable two-phase ratio and the absence of σ-phase. It was found that appropriate heat input (1.68 kJ/cm) and cooling rate (5 °C/s) can effectively avoid the precipitation of σ-phase. Furthermore, the properties of the as-deposited samples were comparable to those of the samples heat-treated at 1300 °C, proving that no subsequent heat treatment was required for 2209 stainless steel fabricated by plasma arc additive manufacture. The samples showed excellent properties, in which the ultimate tensile strength and yield strength were improved by about 7% and 24% compared with GB/T4237-2015. The impact toughness meets the requirements of EN10028-7-2016, which is about 35% higher than that of the cold metal transfer samples, and the corrosion resistance is comparable to that of hot rolled 2205. [ABSTRACT FROM AUTHOR]

Bottles and teats are ubiquitously used for feeding infants and young children. Yet there are limited empirical studies on the scope of infant feeding bottles, their attributes, or their marketing claims. We report the first comprehensive survey on infant feeding bottles and teats in Germany. We aimed to explore the extent of bottles and teats available in Germany, describe their physical attributes and analyze their marketing claims. A cross‐sectional survey of German bottle and teat manufacturer websites was conducted between June and November 2022. Product attributes are presented with descriptive statistics and photographs. Marketing claims are summarized in a descriptive content analysis. We identified 41 brands encompassing 447 unique products (226 bottles, 221 teats). The majority of bottles were plastic (147, 65%) or glass (64, 28%), and the majority of teats were silicone (188, 85%). Most brands (38, 93%) promoted products using one or more inappropriate marketing claims, including equivalency to breastfeeding (29, 73%), idealization through technical or medical descriptions (23, 58%), claims on disease prevention (31, 78%), references to naturalness (29, 73%), infant autonomy (10, 25%), and endorsements from parents (10, 25%) or health professionals (11, 28%). The majority of bottles and teats available in Germany appear to be marketed inappropriately and hold the potential to undermine public health recommendations on infant and young child feeding. Therefore, we recommend Germany strengthens legislation on the marketing of bottles and teats in accordance with the International Code of Marketing of Breastmilk Substitutes. Key messages: There is limited research on infant feeding bottles and teats or their marketing claims.Most infant feeding bottle brands identified (38, 93%) promoted products using one or more inappropriate marketing claims.No national legislation currently exists to restrict misleading marketing claims on infant feeding bottles and teats.Large bottle volumes, teats designed for feeding complementary foods and nonstandardized language for teat flow rates may promote overfeeding, overweight and obesity.Bottles and teats should be made of safe materials, be designed for easy cleaning, meet specified European standards and reference the European safety standard. [ABSTRACT FROM AUTHOR]

An atmospheric plasma spray deposition process was adopted for coating regular-shaped, Stellite 6 powder directly on a rolled 3mm size AISI 304 austenitic grade stainless steel substrate without any intermediate bond layers. Coating thickness as measured in a scanning electron microscope was obtained as 74 μm, 128 μm, and 215 μm. An experimental investigation of the functional behavior such as corrosion, microhardness, and erosion of the coated steel at different operating temperatures was undertaken to determine the suitability of its application in the industry. Erosion tests were conducted in an air jet tribo-tester utilizing alumina as an erodent with normal impingement angle at room temperature, 300∘C, and 600∘C. It was difficult to identify a single coating thickness that can be satisfactorily used for superior erosive wear properties with corrosion resistance. So modern management tools such as tri-vector and technology sieve analysis procedures as identification techniques were adopted for the selection of the best coating thickness by complying with the mechanical, erosion, and corrosion resistance properties. Steel coated with 128-μm coating thickness provides the best result for a combination of functional characteristics. [ABSTRACT FROM AUTHOR]

Background: Basicervical femoral neck fracture is a rare proximal femur fracture with a high implant failure rate. Biomechanical comparisons between cephalomedullary nails (CMNs) and dynamic hip screws (DHSs) under torsion loading are lacking. This study compared the biomechanical performance of three fixations for basicervical femoral neck fractures under torsion load during early ambulation. Methods: The biomechanical study models used three fixations: a DHS, a DHS with an anti-rotation screw, and a short CMN. Finite element analysis was used to simulate hip rotation with muscle forces related to leg swing applied to the femur. The equivalent von Mises stress (EQV) on fixation, fragment displacement, and strain energy density at the proximal cancellous bone were monitored for fixation stability. Results: The EQV of the short CMN construct (304.63 MPa) was comparable to that of the titanium DHS construct (293.39 MPa) and greater than that of the titanium DHS with an anti-rotation screw construct (200.94 MPa). The proximal fragment displacement in the short CMN construct was approximately 0.13 mm, the greatest among the constructs. The risk of screw cutout for the lag screw in short CMNs was 3.1–5.8 times greater than that for DHSs and DHSs with anti-rotation screw constructs. Conclusions: Titanium DHS combined with an anti-rotation screw provided lower fragment displacement, stress, and strain energy density in the femoral head than the other fixations under torsion load. Basicervical femoral neck fracture treated with CMNs may increase the risk of lag screw cutout. [ABSTRACT FROM AUTHOR]

Precipitation hardening (PH) stainless steels, such as 15-5PH, have a high strength combined with excellent corrosion resistance. These properties make them valuable in critical industries such as defence, construction, aerospace, energy and maritime. Recent advancements in additive manufacturing (AM) technology enable the rapid and cost-effective production of components. In the case of 15-5PH components manufactured using wire arc additive manufacturing (WAAM), the as-deposited mechanical properties are not suitable at present for industrial applications. This paper explores the mechanical properties of this process and alloy combination without post weld heat treatment with the aim of eventual adoption in this condition by industry. The impact of weld heat input on the microstructure and mechanical properties of stainless steel 15-5PH produced using WAAM was investigated. The microstructure was examined using hardness testing in addition to optical and electron microscopy. Furthermore, mechanical properties were measured with tensile and impact testing. Investigations were conducted on material produced using weld heat inputs of 0.223 kJ/mm and 0.565 kJ/mm. These results indicate that reducing the weld heat input leads to a minor decrease in strength but an 80% increase in impact toughness. This reduction in weld heat input is correlated with a 50% reduction in volume fraction of δ-ferrite while also noting a 55% increase in carbide precipitates. In addition, the fracture surfaces were predominantly cleavage or quasi-cleavage in morphology. [ABSTRACT FROM AUTHOR]

This paper presents a thorough manufacturability study of 2507 super duplex stainless steel (SDSS) produced by the Laser Powder-Directed Energy Deposition (LP-DED) process. First, experimental observations on single-track surface morphology and geometrical characteristics are described. Then, dimensional and porosity analyses of thin walls and bulk samples are presented and discussed in order to identify the optimal process parameter combinations, from a process point of view, for further characterizations to determine the general properties of LP-DED-printed samples. Finally, the results obtained on wrought steel of the same grade are compared to those of the printed material in terms of microstructure, texture, and ferrite/austenite ratio. A set of meticulously chosen process parameters with regard to the process and the machine (nozzle size, maximum power deliverable) gives the optimal results for the as-built LP-DED material in terms of porosity and microstructure quality but with smaller grains (irrespective of the phase studied) and a higher proportion of ferrite (about 75%). [ABSTRACT FROM AUTHOR]

To improve the corrosion resistance and interfacial contact resistance (ICR) 316L stainless steel bipolar plates used in proton exchange membrane fuel cells (PEMFCs), a series of three-layer amorphous carbon films were prepared by magnetron sputtering. The corrosion resistance and ICR of 316 L stainless steels are greatly improved by the Cr, N doped amorphous carbon and multilayer film structure. Ti and CrN were basement layer and transition layer, and amorphous carbon doping with Cr and N was the top layer. Nitrogen atoms, as the variable atoms, were added into the top layer, focusing on the relation between the N content and the film properties. First principles calculations were used to analyze the bond structure by Cr, N doping into amorphous carbon structure and to determine the reasons for the structural changes in the coating after doping the elements. The results revealed that the films are about 1.05 μm thick and without apparent defects. With increasing nitrogen flow rate, Cr–N bonds and C–N bonds appeared in the coating while promoting the graphitization of amorphous carbon. Compared with that of Cr-doped amorphous carbon coated steel, the corrosion current density of Cr, N co-doped amorphous carbon decreased to 8.1 × 10−9 A/cm2 in the +0.6 V (vs. SCE) potentiostatic polarization test, and as the ICR decreased to 1.3 mΩ cm2, the film exhibited outstanding corrosion resistance and conductivity properties. The Cr, N co-doped amorphous carbon/CrN/Ti composite film formed on 316L stainless steel might be appropriate used in PEMFCs. • Cr, N co-doped amorphous carbon - CrN–Ti composite coatings are prepared. • Cr–N bonds and C–N bonds appear in the coating and influence the property. • Nitrogen addition improves coatings corrosion resistance and ICR. [ABSTRACT FROM AUTHOR]

Newly synthesized gemini quaternary ammonium salts (QAS) with different counterions (bromide, hydrogen chloride, methylcarbonate, acetate, lactate), chain lengths (C12, C14, C16) and methylene linker (3xCH2) were tested. Dihydrochlorides and dibromides with 12 carbon atoms in hydrophobic chains were characterized by the highest biological activity against planktonic forms of yeast and yeast-like fungi. The tested gemini surfactants also inhibited the production of filaments by C. albicans. Moreover, they reduced the adhesion of C. albicans cells to the surfaces of stainless steel, silicone and glass, and slightly to polystyrene. In particular, the gemini compounds with 16-carbon alkyl chains were most effective against biofilms. It was also found that the tested surfactants were not cytotoxic to yeast cells. Moreover, dimethylcarbonate (2xC12MeCO3G3) did not cause hemolysis of sheep erythrocytes. Dihydrochlorides, dilactate and diacetate showed no mutagenic potential. [ABSTRACT FROM AUTHOR]

This study has been conducted on the machining of AISI 304 L stainless steels, which are difficult to machine, have chip-breaking problems, and therefore cause premature wear. A full factorial experiment was designed, and the experiments were conducted at five different inserts, five different cutting speeds, two different feeds, and three different cutting depths. As a result of the experiments carried out, the flank wear and surface roughness values were measured. Utilising Taguchi, Response Surface Methodology (RSM), and Artificial Neural Networks (ANN), interpolation estimates were obtained for flank wear and surface roughness, followed by optimisation investigations. The method with the least error was selected by examining the estimation results. Different methods confirm each other, and simultaneously, the chosen method strengthens the estimation. Confirmation experiments were performed for the parameters giving the optimum value. The optimal outcomes in the range of cutting tips and parameters were obtained with the insert with Al2O3+TiCN coating at a cutting speed of 170 m/min, a feed of 0.13 mm/rev, and a depth of cut of 1.1 mm. It has been seen that the validation experiments agree with the actual and estimated values. [ABSTRACT FROM AUTHOR]

Heat-assisted forming is gaining increasing attention for its potential in improving the formability and quality of metallic bipolar plate (BPP) of proton exchange membrane fuel cell (PEMFC). However, the effects of heat-assisted forming and the subsequent coating process on corrosion resistance and electrical conductivity of stainless steel BPP still remain unclear. This work proposes a way to improve simultaneously the corrosion resistance and electrical conductivity of heat-assisted forming stainless steel BPP by depositing a Cr–C coating directly on its surface without removing the oxide layer using the magnetron sputtering method. Potentiodynamic tests indicate that self-corrosion current density and corrosion current density at 1.0 V (vs. Ag/AgCl) of the Cr–C coated heat-assisted forming SS316L BPP prepared under 900 °C for 10 min are 0.021–0.040 μA cm−2 and 77.54 μA cm−2, respectively, both of which are smaller than those of coated SS316L BPP formed under room temperature. In addition, the contact resistance is close to that of the gold-plated copper plate under the same pressure. The corrosion resistant intermediate oxide layer and conductive network formed between Cr–C coating and metal substrate through defects of oxide layer may be the main reason for improvement of its corrosion resistance and electrical conductivity, respectively. [Display omitted] • A Cr–C coated heat-assisted forming bipolar plate with high performance is proposed. • Self-current densities of 0.022–0.056 μA cm−2 in fuel cell environment is obtained. • The retained intermediate oxide can contribute to a better corrosion resistance. • A lower electrical contact resistance approaching the gold coated copper is achieved. • The conductive network formed is beneficial for electrical conductivity improvement. [ABSTRACT FROM AUTHOR]

Improving the properties of metallic bipolar plates is very crucial for high performance of proton exchange membrane fuel cells (PEMFCs). Cr–C films are prepared on the stainless steel 316L substrate by RF multi-point magnetron co-sputtering of Cr sheets and graphite target for the first time. Effect of the number of Cr sheets on the morphology, composition, corrosion resistance, conductivity, and hydrophobicity of Cr–C films are investigated systematically. With the increase of the number of Cr sheets, the ratio of sp2/sp3 hybrid in the Cr–C films is decreased, and the films become more compact and smoother. When the number of Cr sheets is 8, the ratio of sp2/sp3 hybrid is 5.01, and the Cr–C film shows the best comprehensive performance. The corrosion current densities of anode and cathode are 0.31 μA cm−2 and -0.087 μA cm−2 at constant potential, respectively, and 0.229 μA cm−2 and -0.276 μA cm−2 at galvanic potential, respectively. The corrosion resistance property of the Cr–C film is superior to DOE standards. Compared with uncoated 316L stainless steels, the properties of corrosion resistance, conductivity, and hydrophobicity of the ones coated with the Cr–C films have been improved significantly. This work opens up a new way for the preparation of metal bipolar plate films. • A method for RF multi-point magnetron co-sputtering is proposed. • The effect of the number of sheet on the properties of CrC films is studied. • CrC films with excellent corrosion resistance and hydrophobicity are prepared. • The films deposited with the number of 8 Cr sheets has the best performance. [ABSTRACT FROM AUTHOR]

Via high-throughput first principle calculations based on density functional theory (DFT), doping elements that can improve the corrosion resistance of stainless steel bipolar plates' passivation layer in PEMFCS working environment were screened. Calculation models were constructed based on the (10 12) facet of Cr2O3and 48 elements were doped and 228 doping structures were considered. According to the doping structure and displacement energy, the doping elements were divided into 4 doping types, so that different adsorption and vacancy schemes were adopted. Then the effects of each doping element on the work function, F adsorption energy and Cr/O vacancy formation energy were calculated. The calculation result shows that C, N, In, and Ru can improve all the corrosion resistance parameters of the stainless steel passivation layer; Au, Rh, Pt, Ir, Co and Ni can also effectively improve the corrosion resistance, but there are problems such as price or harm to the proton membrane; Ag, Cu, Sn, and Ge can inhibit vacancy formation and F adsorption, but reduce the work function; Zn can improve the work function and inhibit F adsorption. In addition, the calculation of the electronic density of states shows that the stable bonding formed between the doping atom and the Cr atoms is an important factor for the improvement of the corrosion resistance parameters. [ABSTRACT FROM AUTHOR]

AbstractThe stainless steel flat plate solar collector is a new type of collector that has a longer lifespan in high-temperature and high-humidity environments. When using stainless steel as the base material of the collector, the microchannel structure is typically employed to increase the heat transfer area and compensate for the lack of heat transfer coefficient of stainless steel. However, the shape of the channel section in microchannel structures affects the flow resistance of the heat transfer medium. This article presented the equation for the optimal feature size of the channel, obtained through fluid theory analysis of the stainless steel flat plate collector. The study analyzed the impact of different section parameters on the flow distribution and pressure drop characteristics of the medium in the channel through numerical simulation. The results showed that for a certain inlet flow rate, the cross-sectional geometry of the microchannel heat-absorbing plate determined the parameters such as the type of core cross-section, the degree of wall urgency, and the geometrical length of the microchannel, which in turn affected the distribution of the fluid in the flow channel and the energy loss. The optimal thermal performance of the stainless steel collector was observed when the width of the micro-channel was 8.7 mm and the corrugation height of the tube group was 3.00 mm. [ABSTRACT FROM AUTHOR]

In this investigation, Ultra-high Hard Armor (UHA) steel plate by Shielded Metal Arc Welding (SMAW) process using the Austenitic Stainless Steel (ASS) electrode. In the first part of this investigation, using the finite element method (FEM), thermal analysis parameters were optimized using bead on plate welds in software code, known as SYSWELD. In the second part, using optimized parameters, a coupled thermo-mechanical analysis on multipass welded fabrication was carried out. Weld thermal cycles were analyzed by simulation and compared with experimentally measured temperature profiles. A double ellipsoidal heat source model was used to simulate the SMAW process. The heating rate and cooling rate were calculated along with residual stresses. This range of heating and cooling rate resulted in untempered martensite in the heat-affected zone (HAZ), confirmed by microstructure analysis and hardness mapping. Good validation was found between the measured and simulated 2D model with a 4–10% variation. This study suggests that numerical simulation is the capable technique in understanding the thermal and mechanical properties that influence the welding of ultra-high hard armor steels joints. [ABSTRACT FROM AUTHOR]

Current research studies devoted to cutting forces in drilling are oriented toward predictive model development, however, in the case of mechanistic models, the material effect on the drilling process itself is mostly not considered. This research study aims to experimentally analyze how the machined material affects the feed force (Ff) during drilling, alongside developing predictive mathematical–statistical models to understand the main effects and interactions of the considered technological and tool factors on Ff. By conducting experiments involving six factors (feed, cutting speed, drill diameter, point angle, lip relief angle, and helix angle) at five levels, the drilling process of stainless steel AISI1045 and case-hardened steel 16MnCr5 is executed to validate the numerical accuracy of the established prediction models (AdjR = 99.600% for C45 and AdjR = 97.912% for 16MnCr5). The statistical evaluation (ANOVA, RSM, and Lack of Fit) of the data proves that the drilled material affects the Ff value at the level of 17.600% (p < 0.000). The effect of feed represents 44.867% in C45 and 34.087% in 16MnCr5; the cutting speed is significant when machining C45 steel only (9.109%). When machining 16MnCr5 compared to C45 steel, the influence of the point angle (lip relief angle) is lower by 49.198% (by 22.509%). The effect of the helix angle is 163.060% higher when machining 16MnCr5. [ABSTRACT FROM AUTHOR]

Aluminum, traditionally the primary material for battery casings, is increasingly being replaced by UNS S 30400 for enhanced safety. UNS S 30400 offers superior strength and corrosion resistance compared to aluminum; however, it undergoes a phase transformation owing to stress during processing and a lower high-temperature strength. Duplex stainless steel UNS S 32750, consisting of both austenite and ferrite phases, exhibits excellent strength and corrosion resistance. However, it also precipitates secondary phases at high temperatures, which are known to form through the segregation of Cr and Mo. Various studies have investigated the corrosion resistance of UNS S 32750; however, discrepancies exist regarding the formation and thickness of the passivation layer. This study analyzed the oxygen layer on the surface of UNS S 32750 after secondary-phase precipitation. The microstructure, volume fraction, chemical composition, and depth of O after the precipitation of the secondary phases in UNS S 32750 was examined using FE-SEM, EDS, EPMA and XRD, and the surface chemical composition and passivation layer thickness were analyzed using electron probe microanalysis and glow-discharge spectroscopy. This study demonstrated the segregation of alloy elements and a reduction in the passivation-layer thickness after precipitation from 25 μm to 20 μm. The findings of the analysis aid in elucidating the impact of secondary-phase precipitation on the passivation layer. [ABSTRACT FROM AUTHOR]

Grain boundary (GB) precipitation-induced cracking is a significant issue for S31254 super austenitic stainless steel during hot working. Investigating the deformation behavior based on precipitate morphology and distribution is essential. In this study, continuous smaller and intermittent larger precipitates were obtained through heat treatments at 950 °C and 1050 °C. The microstructure evolution and mechanical properties influenced by precipitates were experimentally investigated using an in situ tensile stage inside a scanning electron microscope (SEM) combined with electron backscatter diffraction (EBSD). The results showed that continuous precipitates at 950 °C had a stronger pinning effect on the GB, making grain rotation difficult and promoting slip deformation in the plastic interval. Continuous precipitates caused severe stress concentration near GB and reduced coordinated deformation ability. Additionally, the crack propagation path changed from transcrystalline to intercrystalline. Furthermore, internal precipitates were a crucial factor affecting the initial crack nucleation position. Interconnected precipitates led to an intergranular fracture tendency and severe deterioration of the material's plasticity, as observed in fracture morphology. [ABSTRACT FROM AUTHOR]

The International Maritime Organization (IMO) is currently rolling out more restrictive regulations in order to achieve net-zero GHG emissions by 2050. In response, the shipping industry is planning to pivot to green energy sources such as hydrogen fuel. However, since hydrogen has an extremely low boiling point (−253 °C), materials for storing liquid hydrogen must be highly resistant to low-temperature brittleness and hydrogen embrittlement. A 316L stainless steel is a typical material that meets these requirements, and various welds have been studied. In this study, 3 pass butt welding was performed by applying the FCAW (flux cored arc welding) process to 10 mm thick ASTM-A240M-316L stainless steel, with the size of the fusion zone and HAZ investigated by mechanical testing and heat transfer FE analysis according to process variables, such as heat input, welding speed, and the number of passes. In all cases, the yield and tensile strengths were about 10% and 3% higher than the base metal, respectively. Furthermore, heat transfer FE analysis showed an average error rate of 1.3% for penetration and 10.5% for width and confirmed the size of the HAZ, which experienced temperatures between 500 °C and 800 °C. [ABSTRACT FROM AUTHOR]

Adhesive bonding has proven to be a reliable method of joining materials, and the development of new adhesives has made it possible to use bonding in a variety of applications. This article addresses the challenges of bonding metals such as the aluminum alloy EN AW-5754 and the stainless steel X5CrNi18-10. In this study, the effects of laser cleaning and texturing on the surface properties and strength of two bonded joints were investigated and compared with mechanical preparation (hand sanding with Scotch-Brite and P180 sandpaper). The bonded joints were tested with three different epoxy adhesives. During the tests, the adhesion properties of the bonded surface were determined by measuring the contact angle and assessing the wettability, the surface roughness parameters for the different surface preparations, and the mechanical properties (tensile lap-shear strength). Based on the strength test results, it was found that bonded joints made of stainless steel had 16% to 40% higher strength than aluminum alloys when using the same adhesive and surface preparation. Laser cleaning resulted in maximum shear strength of the aluminum alloy bond, while the most suitable surface preparation for both materials was preparation with P180 sandpaper for all adhesives. [ABSTRACT FROM AUTHOR]

The deposition process during emulsion polymerization can be classified as both particulate and reaction fouling, but a deeper understanding of the deposition mechanism, especially in combination with the polymerization process, is lacking. Here, a more in‐depth understanding of the deposition mechanism is sought by investigating the fouling formation of a Vinyl acetate and Versa 10 copolymer on a heated stainless steel surface during emulsion polymerization. Its deposition behavior is also compared with the behavior of an already reacted polymer. All possible influencing factors are investigated separately, and the fouling is quantified by the mass based fouling resistance and the fouling layer composition. The fouling rates of both experimental approaches (ongoing reaction versus already reacted polymer) are used to determine the fraction of reaction fouling along the reaction pathway. The solids content and the driving temperature difference are identified as the main factors influencing fouling formation. The deposited material is composed of latex particles and emulsifier with particle size and number depending on the respective equilibrium composition of the fluid phase. The reaction fouling rate is correlated with the proportion of free initiator radicals and the amount of dissolved monomer in the aqueous phase. [ABSTRACT FROM AUTHOR]

A hybrid mold is developed, with its structure including some components made of polymer, as a variant to a classical structure. This hybrid mold is destinated to manufacturing, by cold plastic deformation, of stainless steel thin parts, in particular of certain 0.1 mm thickness stainless steel bipolar plates (BPPs) from proton exchange membrane fuel cell stacks. The mold conceptual and designed main data are revealed. Numerical simulation and analysis by a structural FEA method is applied. A general evaluation is unrolled, with the results referring to the technical – economic use of the developed hybrid mold. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to investigate the effect of laser peening (LP) on mechanical and wear properties of 304 stainless steel sheet. Design/methodology/approach: Three-dimensional morphology, micro-hardness and micro-structure of shocked samples were tested. The wear amount, wear track morphology and wear mechanism were also characterized under dry sliding wear using Al2O3 ceramics ball. Findings: The LP treatment generates deformation twins that contribute to the grain refinement and hardness increase. The wear test displays that the wear mechanism of samples is mainly abrasive wear and oxidation wear at 10 N load. While at 30 N, the delamination and adhesion areas of treated sample are reduced visibly compared to untreated ones. Originality/value: This study specifically investigates the mechanical and wear properties of 304 stainless steel after the direct action of LP on its surface, which shows an effective improvement on the wear resistance. For example, the wear loss of processed sample is reduced by 19% at 30 N, the friction coefficient decreases from 0.4714 to 0.4308 and the groove depth is reduced from 78.1 to 74.4 µm under same condition. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0007/ [ABSTRACT FROM AUTHOR]

Surface roughness and wettability, which characterize the texture formed on the implant surface, are critical features for the functionality of the implant. Laser texturing is a promising processing method because of the advantages it provides in creating a particular surface topography on the surface of a metallic implant material with a nanosecond pulsed laser beam. Different experimental combinations were created using a fiber pulsed marking device on the surface of AISI 316LVM implant material using the hatch strategy; textures depending on the scan speed, frequency, and hatch distance were created on the surface. The surface roughness and wettability evaluated the effects of parameters on the texture form. Based on the experimental and statistical results, while the scan speed was the most significant parameter affecting the wettability behavior and surface roughness, the hatch strategy and frequency also affected the surface roughness to some extent. Many textured surfaces showed super-hydrophilic behavior with a contact angle of 0 ∘ . It has been determined that surface textures with the same or close roughness values did not exhibit the same wettability behavior. The lowest surface roughness of 2 μ m with a 1 3 2 ∘ contact angle was obtained at a hatch strategy of 0 ∘ / 9 0 ∘ , a scan speed of 900 mm/s, a frequency of 100 kHz, and a hatch distance of 0.03 mm. Three-dimensional surface images show that while many craters formed the surface textures, overlapping consecutive beams and hatch strategies significantly affected the surface topography. [ABSTRACT FROM AUTHOR]

For biomedical applications, hydroxyapatite and carbon nanotubes are currently being applied over duplex stainless steel (DSS) alone in order to increase corrosion resistance and biocompatibility. A composite of hydroxyapatite and multi-walled carbon nanotubes was used to improve biocompatibility, osseointegration, and corrosion resistance on 2205 DSS using electrophoretic deposition. The study investigates the effects of potential and time on the properties of the deposited layer in order to determine electrophoretic deposition factor values that are appropriate. The coating properties and effective groups of the phase resulting from this process are determined by Fourier transform infrared spectroscopy and X-ray diffraction. The antibacterial properties of E. coli bacterial strains are investigated for the coated layer. The adhesion between the hydroxyapatite and multi-walled carbon nanotube layers on the 2205 duplex stainless steel substrate was qualitatively evaluated using the adhesive tape test. It was found that the optimal suspension, which consists of 65 weight percent hydrogen acetate and 35 weight percent multi-walled carbon nanotubes, had a homogeneous morphology, a thick structure, and no cracks when coated at 50 V for two minutes. [ABSTRACT FROM AUTHOR]

The chemical components and mechanisms underlying the toxicity and adverse health effects of particulate matter (PM) in the atmosphere have not been fully elucidated. After designing a small, openable, stainless steel cyclone to collect PM samples effectively in powder form for use in toxicological experiments, we evaluated its performance. We compared it with a commercially available aluminum cyclone of similar dimensions, but which is unopenable. The aerodynamic cutoff diameter of the openable cyclone was found by experimentation to be approximately 0.2 µm at a flow rate of 90 L min−1, which is comparable to the unopenable commercial cyclone. The sampling yields, representing the fraction of obtained sample mass relative to the total mass of PM with aerodynamic diameter smaller than 2.5 μm (PM2.5) drawn into the sampler, were approximately 1.3 times higher, on average, for the openable cyclone than for the unopenable cyclone. The openable design of the cyclone might contribute to a marked increase in the finally obtained amounts of PM samples. Analyses of metal concentrations in the PM samples collected simultaneously using the stainless steel openable cyclone and aluminum unopenable cyclone suggest that the stainless steel cyclone is less likely than the aluminum cyclone to cause sample contamination from its material. The openable cyclone developed for this study facilitates the effective collection of powder-form PM samples suitable for use in toxicological experiments. [ABSTRACT FROM AUTHOR]

This research has developed a fabricating process of thin‐strain sensor by utilizing wafer‐level‐packaging (WLP) techniques. The thickness of sensor makes thinner, its performance is able to highly increase. However, the thinner sensor was fragile, and so it was difficult to handle in post processes. Thus, a thin sensor with lid by utilizing WLP techniques, which is tough to break even when handled, is proposed in this research. More than 250‐µm‐deep grooves were fabricated around the lid by deep reactive ion etching. After the lid substrate was bonded on the sensor substrate with a resin, the sensor and lid substrates were respectively polished to 50 and 200 µm thickness. The lids were released along the grooves, and the 50‐µm‐thick strain sensors were able to be fabricated by utilizing WLP techniques. This sensor was used as a diaphragm to measure pressure. The sensors were assembled on a stainless steel housing without breakage. The performance of the developed sensor was almost showed with a conventional pressure sensor. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) provides exceptional geometrical freedom to the architects and designers and enables the construction of architecturally exposed steel structures. However, the AM structural elements inherently possess microscale defects that can affect their ductility. This study aims to identify the fracture-initiating mechanism in AM 17-4 stainless steel that is popularly used owing to its excellent engineering properties. To this end, axisymmetric cylindrical notched and unnotched tension specimens are manufactured employing direct metal laser sintering from 17-4 stainless steel powder with established processing and build parameters. The test specimens were manufactured using a 90° build orientation with the build plate and a layer thickness of 40 μm. Postprocessing heat treatment was avoided as the study focused on understanding the failure mechanism in as-built AM test specimens. Detailed metallurgical analysis is performed employing scanning electron microscopy (SEM) and electron backscatter diffraction. Subsequently, micro–computed tomography (CT) studies are conducted on the tension specimens before and after mechanical testing. Although the SEM analyses of fracture surfaces are inconclusive, the micro-CT analysis revealed evidence of nucleation of new microvoids, growth of existing voids, and void coalescence in the vicinity of the fracture surface, which is unequivocal evidence for ductile fracture. Furthermore, the larger AM defects were found to play an important role in lowering the ductility in addition to stress concentration, and the fracture was initiated when the AM defects coalesced over a length of around 600 μm. The conclusions of this study emphasize the importance of controlling the maximum size of defects in AM structural elements to improve their performance. [ABSTRACT FROM AUTHOR]

The effects of current collectors on the battery performance have significant role, especially in aqueous electrolyte Al-ion batteries, as corrosion effects lead to rapid capacity degradation over cycles. To overcome this problem, we present a study investigating the selection of suitable current collectors and their impact on battery performance. Four different current collectors are selected for this. Stainless steel (SS), nickel foil (Ni), titanium foil (Ti) and graphite plate (GP). It has been proven by corrosion tests, cyclic voltammetry and charge-discharge studies that GP is the best current collector by minimizing the corrosion effect and H2 evolution reaction (HER). The anatase phase TiO2 used with GP current collector provides a 249 mAh g−1 initial discharge capacity at a current density of 3 A g−1, while inferior or no electrochemical activity is observed with Ti, SS, Ni current collectors. The observations here provide insights into the selection of corrosion-resistant current collectors to achieve stable battery performance in the field of aqueous electrolyte Al-ion batteries. [ABSTRACT FROM AUTHOR]

The laser-based thermomechanical joining process was adopted to produce hybrid components made of AISI 304 stainless steel and semi-transparent thermoplastic materials, i.e. polypropylene and polyamide. The process parameters, i.e. laser power, laser-polymer interaction time, and metal surface texture, were optimized using the full factorial experimental approach, and the joints' quality and performance were examined to determine the best operational parameters' combination. Shear tests were carried out to evaluate the resistance of the joints, while morphological and fracture surface analyses were performed to have a better understanding of the phenomena that emerged during the joining process. The findings demonstrated that the shear force and the joint area were significantly influenced primarily by the texture, followed by the laser power, and finally the interaction time. The optimal combination allowed the realization of joints whose maximum shear force reached around 750 N for polypropylene and around 2200 N for polyamide, achieving respectively 60% and 53% of the tensile force of the polymer base materials. [ABSTRACT FROM AUTHOR]

Electromagnetic welding, also referred to as magnetic pulse welding, is a solid-state welding method utilized for joining two distinct materials through high velocity impact. The direct fusion of stainless steel with titanium poses various difficulties owing to the absence of metallurgical compatibility and the occurrence of brittle intermetallic compounds such as FeTi and CrTi. To tackle these challenges, a sustainable, low heat input method like impact welding was applied to address the metallurgical compatibility of the two metals. In this study, a new technique involving aluminum foil, silver foil, and nitinol powder as intermediary materials was investigated to establish a fresh bimetallic structure between Ti-SS304L. Thorough analysis of microstructures, interface formations, and reactions was conducted using scanning electron microscopy and X-ray diffraction. The outcomes showcased successful prevention of intermetallic phase formation through the incorporation of these intermediary materials. Microhardness measurements indicated the absence of brittle FeTi and CrTi phases at the welding interface. Additionally, the weld interface was observed to be situated amid two intermetallic layers at the Ti-SS304L interface, ensuring resistance against corrosion. This inventive method not only averted the creation of harmful intermetallic compounds but also bolstered the overall strength and corrosion resilience of the joint between titanium and stainless steel. The micro hardness obtained at Ti-SS304L interface is 305 Hv and also improved 20% at interface of interlayer materials. [ABSTRACT FROM AUTHOR]