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Three types of steels were designed on the basis of GX40CrNiSi25-12 austenitic heat resistant steel by adding different Mn contents (2wt.%, 6wt.%, and 12wt.%). Thermodynamic calculation, microstructure characterization and mechanical property tests were conducted to investigate the effect of Mn addition on the microstructure and mechanical properties of the austenitic heat resistant steel. Results show that the matrix structure in all the three types of steels at room temperature is completely austenite. Carbides NbC and M23C6 precipitate at grain boundaries of austenite matrix. With the increase of Mn content, the number of carbides increases and their distribution becomes more uniform. With the Mn content increases from 1.99% to 12.06%, the ultimate tensile strength, yield strength and elongation increase by 14.6%, 8.0% and 46.3%, respectively. The improvement of the mechanical properties of austenitic steels can be explained by utilizing classic theories of alloy strengthening, including solid solution strengthening, precipitation strengthening, and grain refinement. The increase in alloy strength can be attributed to solid solution strengthening and precipitation strengthening caused by the addition of Mn. The improvement of the plasticity of austenitic steels can be explained from two aspects: grain refinement and homogenization of precipitated phases. [ABSTRACT FROM AUTHOR]

Combined innovative technology developed in this article makes it possible to produce bimetallic long products in the form of bars and wires with improved mechanical properties, due to the ultrafine grain structure of the material, with less energy and labor costs and implementation of continuity principle in industrial enterprises of metal-working industry. The combination of equal-channel angular pressing with drawing makes it possible not only to harden the composition, but at the same time to preserve important and regulated by a number of GOST plastic properties of the products. This circumstance favorably distinguishes the method under study from other (traditional) types of deformation treatment. [ABSTRACT FROM AUTHOR]

The disposal of oily wastewater is a severe environmental problem faced by the metalworking and automobile industries. When released into the environment, oil-contained wastewater severely threatens plant, animal, and human life. Adsorption has emerged as a unique technique, and using natural adsorbents makes it further cheap and more eco-friendly. Removal of both free and emulsified oil from wastewater by using biosorbents was looked upon as an alternative. The present research aims to develop a novel biosorbent from teak (Tectona grandis) leaves suitable for removing oil from wastewater. Batch Sorption studies were carried out by varying pH, sorbent dosage, contact period, mixing speed, and initial oil concentration. The optimum conditions for maximum adsorption efficiency were determined. The results showed that the adsorption of oil onto teak leaf (Tectona grandis) adsorbent follows Freundlich isotherm with a maximum sorption capacity of 10.115 mg/g and a pseudo-second-order kinetic model. The thermodynamic parameter (ΔH = 5033.75 KJ/mol) suggested oil adsorption's spontaneous and endothermic nature onto the teak leaf (Tectona grandis) adsorbent. The best regeneration efficiency was achieved with 0.01 M HCl. [ABSTRACT FROM AUTHOR]

This article questions the cross-cultural ethnographic insight of metalworking as a male craft, commonly performed in male spaces (workshops) away from female members of society, through the analysis of archaeological evidence for the household-based metal production within multi-gendered and multi-generational households and corresponding but rare ethnographic examples. [ABSTRACT FROM AUTHOR]

At present, powder materials are used in almost all known branches of science and technology such as the automotive industry and metalworking, medicine and nuclear research. This is a wide range of structural and tool materials, and special-purpose materials that have good heat resistance, wear resistance, and resistance within corrosive media. Ultrafine powders are used extensively in development of new functional materials and nanomaterials, since an increase in the discrete nature of structural elements leads to a significant change in material properties. [ABSTRACT FROM AUTHOR]

To improve the nitrogen-expanded crystalline structure, tribological and anti-corrosion properties in industrial field, nitrogen atoms were incorporated into 65Mn steel by plasma nitriding. In this study, 65Mn steel was processed using a plasma nitriding method at 600 °C for the improvement of tribocorrosion resistance. The structural evolutions, chemical elements and chemical bonds of obtained nitrided sample were investigated using a scanning electron microscope, electron dispersive spectroscopy and X-ray photoemission spectroscopy, respectively, and the effects of normal load on the coefficient of friction and wear rate in 0.1 mol/L Ca 3 (PO 4) 2 solution were investigated using a reciprocating ball-on-plate wear tester. The polarization and electrochemical impedance spectroscopy of nitrided sample in Ca 3 (PO 4) 2 solutions were conducted using an electrochemical workstation. The results show that the average coefficients of friction of nitrided samples are decreased from 1.047 to 0.420, and the corresponding wear rates are ranging from 6.274 to 11.250 under the normal loads of 2–10 N. The presence of nitrided layer originated from the plasma nitriding process plays roles of the high hardness and excellent tribocorrosion resistance. The wear mechanism is a combination of abrasive wear and adhesive wear, which is attributed to the formation of hard nitrides. Moreover, the corrosion resistance of nitrided sample is improved by the formation of passive film and the band gap energy of Fe 4 N. • The tribocorrosion and electrochemical properties of plasma nitrided 65Mn steel are improved by LR. • The charge transfer resistance of plasma nitrided 65Mn steel is larger compared with the original 65Mn steel. • The tribocorrosion and corrosion models of nitrided 65Mn steel are revealed by the DFT calculation. • The enhancement of wear and corrosion properties is attributed to the Fe 4 N phases with larger band gap energy. [ABSTRACT FROM AUTHOR]

This study utilizes active control of welding clamping force through periodic additional force (PAF) to assist in fabricating ultrasonic spot-welded copper-aluminum joints. The microstructural characteristics and mechanical properties of the copper-aluminum ultrasonic spot welded with periodic additional force joints were systematically investigated. Periodic additional force was applied to the welding interface, facilitating plastic deformation and flow. This can transform the relatively smooth weld interface into a wave- and swirl-like surface with a maximum peak height of 12 μm. Simultaneously, the mutual diffusion length of copper and aluminum at the weld interface increased from 2 μm to 8 μm. Additionally, the weld interface of ultrasonic spot welded with periodic additional force exhibited typical {111}〈112〉 or {111}〈110〉 shear textures, confirming a strong interface bonding. The effect of the periodic additional force on the thermomechanically affected zone (TMAZ) was also examined. It was discovered that lower periodic additional forces enhanced dislocation density and decreased anisotropy, leading to improved mechanical characteristics. The utilization of periodic additional force in assisting ultrasonic spot welded can significantly enhance the lap shear failure force by up to 59.98%. The paper innovatively proposes a control method of reverse periodic additional force, offering a strategy for the preparation of reliable aluminum-copper joints. [Display omitted] • This paper proposed a novel bottom-up active force control ultrasonic spot welded method based on additional forces. • The active additional force was set periodic, providing control over the joint with minimal alteration of input energy. • The introduction of periodic additional force increased the plastic deformation at the Cu/Al interface. • {110}〈112〉 Brass and {110}〈111〉 P(B ND) textures were generated at low periodic additional forces. [ABSTRACT FROM AUTHOR]

Demand forecasting is essential for improving the operational performance of organizations, as well as for decision making in production planning and scheduling processes. Given this context, this research aimed to apply and compare the results of eight quantitative demand forecast methods, classified as seasonal and non-seasonal, in a case study in a metalworking industry. Thus, the methods were used in the forecast of three cast products, arbitrarily denominated as A, Be C, and the data were obtained from the company that manufactures these products. For this, Excel software was used to perform the applications and to create the time series and the accuracy metrics. As conclusions, the Winters Multiplicative Method obtained the best results for products A and C. On the other hand, for product B, the best result was found with the Winters Additive Method. Therefore, the seasonal models presented the best results for these products. That said, with the performance with the demand forecast methods in this research, it was possible to demonstrate the theoretical-practical application in a case study, to understand the behavior of the products analyzed, and to support the organization in question, with regard to decision making and the formulation of efficient strategies in the area. [ABSTRACT FROM AUTHOR]

Metal foundry represents an important sector within the mechanical industry. The method of casting metal into sand molds has been used for millennia because the freedom it allows the designer in terms of size and shape. The objective of this research is to establish a numerical simulation model, experimentally validated, of molten metal pouring in a sand mold, taking as analysis criteria the internal defects in the body of the bearing support of the 4 500 lb. harrow. In this research, an analysis was carried out, from the Finite Element Method (FEM), of casting process taking into account the molten metal pouring temperature, the mold preheating temperature and the filling speed. These parameters were recorded during the experimental testing of the process. An inspection procedure is shown, in which elements of visual analysis of the piece obtained and of simulation by MEF were used to determine the magnitude and location of internal defects inside the piece. The defects were classified in blowhole, porosity and cold junction, a correspondence was appreciated in terms of their location, between the simulated and the experienced models; while the defects area relative error in these models is less than 10%. [ABSTRACT FROM AUTHOR]

The archaeological visibility of the production and consumption of gold and silver ornaments increased substantially during the Iron Age. A large number of precious metalworks rendered with distinctive 'animal style' motifs have been recovered from elite tombs in north‐west China, and have attracted great interest when investigating the dynamics of exchange, mobility and transcultural encounters in Eurasian antiquity. However, little scientific research has been undertaken to examine the manufacturing techniques and metal composition of such 'animal style' artefacts found in north‐west China and its neighbouring areas in a broader Eurasian context. Using multiple non‐invasive analytical methods, we conducted a detailed scientific analysis of two groups of precious metals excavated from Dongheigou Tomb 12 (fourth–second centuries bce) and Xigou Tomb 1 (third–second centuries bce) in present‐day Balikun county, Xinjiang Uygur Autonomous Region. The results suggest that mould‐pressing technology was employed for the production of the 'animal style' appliqués found in these two tombs. The current analysis provides a definitive explanation for the traces of superficial crafting through their specific microstructure and the tool marks of manufacturing, and will thus be of significant interest for further research concerning the metallurgic knowledge and technological practice of precious metalworking industry in north‐west China and Central Asia. [ABSTRACT FROM AUTHOR]

Haynes-25 is a cobalt-based alloy resistant to oxidation and possesses high-temperature properties. Despite the excellent properties, the machinability of Haynes-25 is extremely difficult. Sustainable machining of this alloy is inevitable for producing earth-friendly products. Thus, researchers and scientists have been seeking alternative sustainable technologies to machine these alloys. In the present study, efforts are made to explore the machinability, energy consumption, and economic feasibility of a novel oils-on-water (OoW) lubrication approach mixed with cryogenic liquid nitrogen (LN). Twenty external turning experiments were performed under this novel cryogenic-LN oils-on-water (LNOoW) approach and compared with conventional machining approaches. Machining performance (temperature, cutting power and energy, tool wear and tool life, and surface quality) and economic aspects (production cost) were considered as response metrics. Column graphs are plotted for each metrics to compare the results. The results showed that the proposed LNOoW lubricooling approach reduced the cutting temperature and improved the surface quality of the workpiece significantly. Furthermore, less cutting power and electrical energy consumption were achieved in the proposed cooling/lubrication approach. The novel LNOoW approach also enabled an extension of about 97.56 to 111.11% of cutting tool life as compared to flood-assisted machining process. In addition, 11.76% of surface roughness and 38.725 ¥ cost reduction was obtained at the lowest level of feed rates. It was noted that better economic benefits could be obtained at the highest feed rate and the mid-range levels of cutting speeds. Furthermore, 50% economic benefits are achieved at medium cutting parameters in the LNOoW approach. Overall, the LNOoW approach out-performed in all the metrics. Therefore, the LNOoW approach has a high potential to replace the old cutting technologies. The present work can be used as fundamental guidelines for the machinist working in the metal processing industry to adopt the hybrid LNOoW approach successfully in the machining process. [ABSTRACT FROM AUTHOR]

Difficult-to-cut material, i.e., AISI D2 tool steel, has been widely adopted in metalworking industries to manufacture dies for piercing, blanking, drawing and thread rolling due to its excellent wear resistance and non-deforming properties. This article attempts an experimental study to determine the effect of cryogenic coolant (liquid nitrogen) on the grindability of AISI D2 tool steel as work material and its results are compared with the conventional dry and wet grinding methods. The effects of the cryogenic coolant on force components (i.e., tangential force, Ft and normal force, Fn), specific grinding energy (u), force ratio, surface roughness parameters (Ra and Rz) and microstructure were observed. The comparison results indicate a significant reduction in grindability indices such as 64% and 44% in Ft, 54% and 34% in Fn, 46% and 30% in Ra and 40% and 34% in Rz, respectively under cryogenic grinding at higher downfeed as followed to dry and wet grinding. The grinding performance in Ft, Fn, u and Ra was also improved with an increased delivery pressure of the liquid nitrogen (LN2). From the results, it is concluded that cryogenic coolant offers an influential method to improve grinding performance and surface integrity of AISI D2 tool steel. [ABSTRACT FROM AUTHOR]

Three halogen-free poly(ionic liquid)s (PILs), composed of polycations (poly(PEGMA-co-METAC), PPM) and different amino acid anions as counterions, were synthesized. The physicochemical properties of three PILs were characterized to confirm their efficacy as viscosity-enhancing additives. The tribological properties of aqueous lubricants containing PILs were investigated by the SRV-IV test. The addition of three PILs to water resulted in remarkable improvements in kinematic viscosity, lubricity, and anti-wear properties. Among them, PPM-Try demonstrated the best tribological performance due to the formation of the more superior protective film on the friction interface through a tribochemical reaction. Furthermore, PPM-Try is non-toxic to environment and demonstrates favorable antibacterial properties, rendering it a promising eco-friendly aqueous lubricant additive for applications in the metalworking and food industry. [Display omitted] • Three halogen-free PILs with amino acids counterions were prepared and employed as water-based lubricant additives. • PILs can significantly enhance the viscosity, corrosion resistance, friction reduction and anti-wear properties of water. • Three types of tribofilms act synergistically to endow PILs with superior tribological properties. • PPM-Try demonstrates favorable antimicrobial activities and low biotoxicity towards earthworm. [ABSTRACT FROM AUTHOR]

The conductive nano-Al/polyaniline composites were prepared by the milling method in the solid state. Here, aluminum nanostructures were prepared in two different mechanical methods, wire drawing and wire milling in the presence of lubricant oil. The effects of the preparation methods on the structures and morphologies of aluminum nanostructures were investigated by XRD and FESEM. The results show that the shape and size of aluminum nanoparticles in the preparation by the wire drawing method are significantly different than the wire milling method. The aluminum nanostructures were prepared by milling method have flake-like nanosheets while the wire drawing method leads to the formation of spherical ultrafine nanoparticles, which particles size are in the range of 30–60 nm. Then, polyaniline was produced using a solid-state polymerization process by the chemical reaction between aniline hydrochloride and potassium peroxydisulfate. Finally, nano-Al/polyaniline composites were prepared by mechanical milling at room temperature. The quantitative analysis was carried out with the materials analysis using diffraction (MAUD) method and weight fraction for aluminum and PANI were calculated 6.66% and 93.34%, respectively. Electrical conductivity measurements show the conductivity (1.2 × 10−2 S cm−1 at 25 °C) for polyaniline emeraldine salt and (1.02 × 10−3 S cm−1 at 25 °C) in nanocomposite respectively. The results show that by adding aluminum nanoparticles to the polymer the conductivity of nanocomposite (Al/PANI-ES) is lower than that for pure (PANI-ES). Thermogravimetry and differential thermal analysis curves show pure (PANI-ES) and nanocomposite (Al/PANI-ES) have a similar thermal degradation process. The total weight loss in TG curve of pure PANI-ES, in the temperature range 45–800 °C is 46.28% but, total weight loss observed in nanocomposite is 38.67%. Therefore, nanocomposite has higher thermal stability than that of the pure PANI-ES. [Display omitted] • Mechanochemical preparation of polyaniline. • Polyaniline/aluminum nanocomposite was prepared in a novel method in the solid state. • A novel method in the preparation of monodisperse aluminum nanoparticles in wire drawing. • In the milling method a flack-like sheets aluminum nanostructures were obtained. • Wire drawing prepared aluminum nanoparticles have less strain than the wire grinding. [ABSTRACT FROM AUTHOR]

Frequent tool failure and rupturing pose significant challenges in friction stir welding (FSW) of thin dissimilar material sheets with diverse thermal and mechanical properties. These issues exacerbate at higher welding speed (ν), demanding greater precision in welding methodology. This paper presents a novel approach to weld 300 μm thin SS304 and 500 μm thick commercially pure aluminum sheets at ν up to 2400 mm/min using H13 tool without wear, obviating the necessity for expensive high-strength tool materials. Furthermore, the use of a pinless tool negates the requirement for an additional pinhole filling step, which is a prevalent challenge associated with pinned tools. The study unveils that higher tool tilt angle (α) reduces flash formation, leading to a higher effective weld thickness, thereby enhancing weld strength. The increased material extraction (2.048 mm3) from the weld center and higher heat generation (7.6%) compared to the pinless tool imposes a speed limit of 300 mm/min for the pinned tool. The thicker layer (4.9 μm) of inter-metallic compounds (IMC) formed at lower ν showed maximum joint strength (70.03% of base Al). The fracture behavior indicates cleavage facet formation becomes more frequent at higher ν , diminishing joint ductility. With a distortion-free, high lap shear strength and enhanced ν , this novel joining method meets the needs of industrial mass production. [Display omitted] • Friction stir welding of dissimilar thin sheets at high speeds (max: 2400 mm/min). • Utilization of a low-cost H13 pinless welding tool, demonstrating zero tool wear. • Use of a pinless tool eliminates the need for an additional pinhole-filling process. • Distortion and defect-free diffusion-based joint with lap shear strength of 70.03%. • Varying IMC layer thicknesses at different speeds determine weld strength. [ABSTRACT FROM AUTHOR]

For sub-sized fatigue specimens made of EUROFER97 in unconstrained contact to ceramic breeder pebbles, exposed to purge gas conditions for different durations in an oven, a chemical surface attack was observed which led to a significant reduction of fatigue lifetime [Aktaa et al., 2020]. To better reproduce the flow of the purge gas in the breeding zone of a Helium-Cooled Pebble Bed Breeding Blanket, the experiment was now repeated by placing the same kind of samples in the helium loop HELOKA HEMAT, where the gas is permanently circulated in a closed circuit, and its water content is controllable. The composition of the gas was monitored with a mass spectrometer and humidity sensors. The samples were exposed to a mixture of helium and 0.1vol% hydrogen at DEMO relevant operating conditions (550 °C, 1.2 bars abs.) for a duration of 8, 16, 32, and 64 days, respectively. New sample holders were designed which allow direct contact of the samples with the gas mixture. A special procedure for the handling of the test section was implemented to avoid contact of the hygroscopic pebbles with air humidity during the preparation phase and during the extraction of the samples from the test rig. The present contribution discusses the various considerations on which the test rig design was based, followed by a description of the experimental setup and preliminary results of the testing campaign. These are similar to the results achieved in the oven experiment. In the future, the loop will be used for tests with up to 200 Pa partial pressure of steam in helium; a mixture that is considered relevant for the DEMO purge gas composition. [ABSTRACT FROM AUTHOR]

The effects of pulsed laser interaction with matter have become a center for research. The pulsed laser has become an indispensable manufacturing tool in the efficient machining of polycrystalline diamond (PCD) and other materials. Herein, the ablation threshold and chemical modification of PCD irradiated using ultraviolet (UV) nanosecond laser is scrutinized. Using a UV nanosecond laser source, a bulk of PCD is ablated in air, and multipulse processing is executed at a wavelength of 355 nm. The ablation threshold of PCD is reported to be ≈3.7326 J cm−2 based on the linear relationship between the laser pulse energy density and the crater diameter, with a Gaussian distribution of the laser intensity on the cross‐section. Furthermore, the sp3 structure transitioned to the sp2 graphite phase when the PCD is exposed to UV nanosecond laser irradiation. Consequently, this study provides a theoretical and experimental reference for UV nanosecond laser micromachining of PCD materials in the research and metal‐working industries. [ABSTRACT FROM AUTHOR]

Inhalation is the main route of exposure to airborne pollutants. To evaluate the safety and assess the risks of occupational hazards different testing approaches are used. 3D airway epithelial tissues allow to mimic exposure conditions in vitro, generates human-relevant toxicology data, allows to elucidate the mode of action of pollutants. Gillian3500 pumps were used to collect the airborne particulate from woodworking and metalworking environments. EpiAirway tissues were used to model half working day (4 h), full working day (8 h), and 3 working day exposures to occupational pollutants. Tissue viability was assessed using an MTT assay. For preliminary assessment, RT-qPCR analyses were performed to analyze the expression of gelsolin, caspase-3, and IL-6. Tissue morphology was assessed by hematoxylin/eosin staining. An effect on the proliferation of lung epithelial cell line A549 was assessed. Acute exposure to workspace pollutants slightly affected tissue viability and did not change the morphology. No inhibiting effect was observed on the proliferation of A549 cells. Preliminary analysis showed that both types of particles suppressed the expression of gelsolin, with the effect of metalworking samples being more pronounced. A slight reduction in caspase-3 expression was observed. Particles from metalworking suppressed IL-6 expression. [ABSTRACT FROM AUTHOR]

We report unexpected classical and quantum dynamics of a wave propagating in a periodic potential in high Brillouin zones. Branched flow appears at wavelengths shorter than the typical length scale of the ordered periodic structure and for energies above the potential barrier. The strongest branches remain stable indefinitely and may create linear dynamical channels, wherein waves are not confined directly by potential walls as electrons in ordinary wires but rather, indirectly and more subtly by dynamical stability. We term these superwires since they are associated with a superlattice. [ABSTRACT FROM AUTHOR]

The Sisak Ironworks Metallurgical Combine arose from the former Caprag Smelter (1938). The technological process of Sisak Ironworks had characteristics of integrated ironworks, including mass production of coke, pig iron, and crude steel, as well as rolled semi-finished and finished products, along with its own significant metalworking industry. The primary, and globally recognized, products of Sisak Ironworks were welded and seamless pipes. Sisak Ironworks was characterized by continuous reconstruction and modernization with the desire to expand the product range and improve the quality system of final products. Sisak Ironworks gained 16th place out of the 200 largest companies in former Yugoslavia according to journal „Ekonomska politika“ in 1986. Sisak Ironworks was the largest metallurgical company in the Republic of Croatia, and the third (after Zenica Ironworks and Associated Slovenian Ironworks), and the only producer of seamless pipes in former Yugoslavia. Sisak Ironworks was of great significance for today’ s Sisak-Moslavina County, because in 1978, for example, more than 90 % of the total revenue came from the ironworks, and at the end of 1989, it employed 13,992 workers and produced around 2.07 million tons of metallurgical products (coke, pig iron, crude steel, pipes etc.). Sisak Ironworks always nurtured solidarity; after World War II, it built more than 3,600 apartments, and approved over 4,000 loans for individual construction of houses, participated in the co-financing of numerous infractructural and communal projects, educational, cultural, sports-recreational, and other activities etc. The City of Sisak is not the same without the Sisak Ironworks, which we are still witnessing today. The development of the Sisak Ironworks improved the social and cultural life of Sisak and contributed to its urbanization. In 1939, at the time of the opening of the Caprag Smelter (the forerunner of Sisak Ironworks), the population of Sisak was 12,920, and in 1971, about 40,000, while in 1991, the city of Sisak had 45,992 inhabitants. There has always been a symbiosis between the metallurgical industry and the city of Sisak. Unfortunately, the Sisak Ironworks disappeared a long time ago due to several reasons (war afflictions, three unsuccessful privatizations, negligence of the relevant state institutions, etc.), so that the metallurgical production of the remains of the original Ironworks in 2019 had reduced to crude steel production (69 kt) to the level between 1955 (46.9 kt) and 1956 (82.5 kt). [ABSTRACT FROM AUTHOR]

Technology employed by the ancient goldsmiths is traceable through archaeometallurgy. Using non-destructive analytical methods, namely, a 3D digital microscopy and a scanning electron microscopy with energy dispersive spectrometer (SEM–EDS), we investigated the manufacturing techniques and chemical composition of gold and silver artefacts recovered from Tomb 2 (M2), the richest find from Xigoupan cemetery (fourth-third century BCE) in the northern part of Jungar Banner, Inner Mongolia. The present research contributes to a better understanding of the inventive nature of precious metal working industry in early China (eighth-third century BCE). First, cultural interchange was evidenced in the metalwork examined, notably as being closely linked to techniques emerging from the Eurasian steppes. In Xigoupan M2, the ornamentation of sheet works in the Scytho-Siberian animal style was seen to be clearly influenced by the central Asian steppe goldsmithing practice, while certain cast items were typical of the Chinese tradition. Second, our analysis reveals that the gold appliqués with raised animal figures that were previously thought to be repoussé work have actually been made with double-sided carving. We consider such a new technology as one of local inventions that was inspired by methods arriving from the central Asian steppes. In addition, our analysis of elemental composition reveals that the gold artefacts found in Xigoupan M2 to be made of natural gold, while the horse harness ornament is made of pure silver. These results, combined with the study of the existing data pertaining to comparable examples, attest to the shared craftsmanship in prestige metal production across the northern Chinese states, especially with regard to the pre-imperial period Qin workshop. [ABSTRACT FROM AUTHOR]

Development of more complex hard coatings that can be implemented in increasingly severe and complex conditions is necessary for the evolution of the metalworking industry. Therefore, this research focuses on the synthesis and corrosion study of the [TiCN/TiVCN]n system as a function of the bilayers number. Thus, the structural resulted determined that the quaternary TiVCN coating, which presents very little information so far, presents an FCC structure as the conventional TiCN system, and the inclusion of vanadium atoms that compete with titanium atoms in Wyckoff 4a positions causes a distortion of the crystal lattice that increase with the bilayers number. An increase of 64.3% in the polarization resistance of the multilayers coating with n = 70 bilayers when compared to the n = 1 bilayer. Corrosion rate decreased by 57% when comparing the 70 bilayers coatings with the 1 bilayer coating. The results obtained show that this new multilayer system presents optimum properties to be used as protective coating on engineering devices exposed to high corrosion conditions. •Simulation of (TiCN) Ternary and (TiVCN) Quaternary structures and the multilayer structure. •Analysis of the structural configurations by means of proposed structural models (Hume-Rothery). •Study of the corrosive damage by SEM. [ABSTRACT FROM AUTHOR]

The use of cutting fluid in the grinding process is crucial to guarantee quality in the products. However, most cutting fluids can cause disease to operators and damage the environment, which adds costs to the industry, as well as a deficit in the operator's quality of life. In addition, the metalworking industry has as problem control corrosion in their parts; it demands to add the process of remove cutting fluid of the workpieces and add a protective oil on their surface. In this context, a new class of corrosion inhibitors that use water as a propagation medium, generically known as V-active® VCI, was formulated, which made it possible to develop, firstly, a cutting fluid with the addition of such inhibitor, called generically VCI 1, which would eliminate the process of degreasing and adding protective oil. Previous research has indicated the VCI 1 has an excellent performance in the grinding process, which promoted the development of two other new fluids (named generically VCI 2 and VCI EP) at a reduced market cost to make the product more competitive. In addition to the cost savings compared with the VCI 1, the VCI EP has the differential of an extreme pressure additive. It is noteworthy that the fluids in question pose no risk to humans and are biodegradable. Thus, the performance of these two new fluids with a corrosion inhibitor was verified in the grinding process of AISI 4340 steel with an aluminum oxide grinding wheel and the results were compared with the higher market cost V-active® VCI fluid and with a base fluid without the corrosion inhibitor. The comparison took place at three different feed rates (0.25, 0.50, and 0.75 mm/min). For each feed rate, the following were evaluated: surface roughness; roundness error, diametral grinding wheel wear, microhardness, optical microscopy, and acoustic emission, and the ground surface was analyzed using scanning electron microscopy (SEM). Therefore, useful information was obtained for the technological development of the rectification process, thus adding to scientific knowledge and dissemination of knowledge to society. [ABSTRACT FROM AUTHOR]

Residual stress within metal components represents, in the majority of the cases, a source of a large amount of scrap and losses for the metalworking industry. Although there are methods of measuring residual stresses, the complexity of geometric shapes in several products makes it a difficult task. Current research work developed a new methodology for measuring residual stresses in areas of complex geometry, as is the case of engine blocks in the automotive industry. The strain gauge measurement technique (SMT) is used here to validate the proposed methodology since, for many years, the SMT has gained high confidence in the automotive industry for the case of measurements of residual stress in metallic products. The new methodology involves: firstly, a pair of indentation marks performed at the section of study and secondly, a cutting process which is carried out to relieve stress in the section. Replica samples were taken from both samples in every experiment to measure the distance between indentation marks. Difference between both measurements (the sample before and after the stress relief) gives us a measure of the change in deformation which is related with the residual stress by Hooke's law (σ = F/A = Eε = E[∆ε/(ε0)]), where ε0 is the initial spacing and Δε is the change in the spacing between indentation marks. The implementation of the replica sample allows the transfer of the distance between indentation marks by means of portable samples, which can be carried to the laboratory where an optical microscope is used together with an image analyzer to obtain accurate measurements in laboratories with a resolution of ± 2 μm. Residual stress values by the new technique were then calculated to compare with those values obtained by the strain gauge technique. Findings confirm the effectiveness of the current methodology for measuring residual stresses in complex areas and suggested a great opportunity in which residual stress measurements have not been able to obtain using any other technique. [ABSTRACT FROM AUTHOR]

In many applications in the metalworking industries, mass production of parts with holes possessing critical finish requirements for precision assembly operations demands tolerances in the working range of IT7 to IT5. However, this may not be achieved with regular twist drills, and further finishing processes such as reaming is normally required. To perform reaming, the workpiece needs to be previously drilled, so that two different cutting tools are needed and twice as much time is needed to machine compared with workpieces that need to be drilled, which in turn affects productivity and competitiveness. Therefore, any investment in the production of tools and techniques aiming to reduce the machining time of close tolerance holes, and lower tool wear rates and at a lower cost, will receive special attention from the machining sector. In this context, this paper presents technical and economic analyses of two manufacturing systems in drilling (drilling specially designed drill and regular drill with reamers) of compacted graphite iron (CGI) workpieces. The technical analysis was based on the tool wear mechanism, hole quality, and machining time, whereas the economic analysis was on total machining cost for use of specially designed drill and regular drills followed by reamers. Results showed lower wear on the specially designed drills compared with reamers. Also, the finish and dimensional deviations were similar to those obtained with reamers. Up to 40% of reduction in the machining time was achieved by using the specially designed drill, which resulted in a 57% reduction of the total cost. [ABSTRACT FROM AUTHOR]

Large quantities of coolant–lubricants are still widely used in the metal working industry, generating high consumption and discard costs and impacting the environment. This paper presents the evaluation of the performances of the various machining environments (dry, conventional wet and MQL technique) applied in hard turning of the AISI 4140 high-strength low alloy steel with coated mixed ceramic (CC6050) in terms of surface roughness, cutting force components, and tool wear. For this purpose, a number of machining experiments based on statistical four-factor (cutting speed, feed rate, depth of cut, and cutting radius) and hybrid-level factorial experiment designs uncompleted with a statistical analysis of variance were performed. The results indicate that the resulting cutting force obtained with the MQL machining process significantly improved when compared with other machining processes. For example: FRMQL ≈ 1.08 FRdry and FRwet ≈ 1.37 FRdry. Then, the RSM was utilized to define the optimal machining parameters. Finally, the ranges for best cutting conditions are proposed for serial industrial production. [ABSTRACT FROM AUTHOR]

Owing to the relevance of the turning operation to the metal working industry, intensive research is constantly undertaken in order to improve the quality of manufactured products, optimise production time, and reduce costs. Among the investigated topics, texturing of the cutting tool rake face has received increasing attention since it can affect tool life, process forces, and cutting temperature. The contribution of the present work resides in depicting the procedure for laser texturing the cutting edge chamfer of uncoated tungsten carbide inserts aiming at weakening the stability of the seizure region. Moreover, the performance of textured and non-textured tools was assessed when turning grey cast iron. Two parallel columns of dimples with an average diameter of 40 μm and variable distance between rows of dimples (60, 100, and 200 μm) were produced and the turning experiments were carried out dry and with the application of minimal quantity lubrication (MQL). The findings indicated that the lowest values for the turning force components were obtained when cutting with textured tools possessing dimples 100 μm apart and using MQL. Texturing did not affect tool life in dry turning; however, when cutting with MQL, the longest tool lives were obtained using the tools textured with dimples 60 and 100 μm apart. Finally, machined surface roughness was not affected by tool texturing and decreased slightly with the application of MQL. [ABSTRACT FROM AUTHOR]

Production planning is a medium-term tactical decision that determines the level of employees, inventories, and production required to meet demand on a planning horizon. a mathematical model was designed for aggregate production planning in medium metalworking industry, where a mixed strategy of production planning that included chase (hiring and firing) and level of inventories was developed, from a linear programming model. The results showed the quantity of required employees, hiring, production levels per working shift and inventories, for each process, which minimize the associated costs with the plan and meet the demand requirements. The mathematical model designed and the process followed for the aggregate production planning, are a tool to support decisionmaking in operations management, and can be implemented in companies in the metalworking industry. [ABSTRACT FROM AUTHOR]

Brass is widely used in the machine industry, automotive, shipbuilding, construction, metalworking industries, as well as in the production of fittings. Certain types of brass, despite the almost identical chemical composition and the same form resulting from the standards, e.g. sheets of a certain thickness, often differ in performance, e.g. mechanical properties. The presented work compares selected mechanical properties of CuZn39Pb2 brass sheets from different manufacturers. [ABSTRACT FROM AUTHOR]

The main advantages of socially responsible marketing in the metal-working production of machine-building enterprises are considered. The ways of improving the quality of products that allow the company to increase their profits are described. It is shown that due to the use of obsolete structures of blade tools, the enterprise produces products with reduced productivity or deliberately produces defective parts of machines, which makes use of various machinations for the promotion of products. The mathematical models are proposed, which allow at the stage of production planning to evaluate the quality of the manufactured parts and the technological cost of processing. The parameters of the quality of parts processing on grinding operations are mathematically determined and the conditions for reducing the technological cost of processing and increasing the profit of the enterprise are established. [ABSTRACT FROM AUTHOR]

Metalworking industry, especially welding processes, is one of the most economically active in the world. Transformation and joining of metal parts are used in many labor activities, such as construction. Welding uses different metal mixtures to carry out bonding through various processes. The greatest chemical risk associated with welding is the emission of metallic fumes, which enter the body mainly through the respiratory system, producing effects in all systems of the human body. Therefore, studies are needed to support the control of exposures to these chemicals in the workplace, as well as the limitation of emissions to the environment, by governments, employers, and workers. Research, innovation, development and use of chemicals advance very fast, especially in welding where new mixtures or metal alloys are used every day. However, knowledge of the effects of these chemicals does not advance at the same speed. This review intends to make a compilation of investigations on the last 20 years about exposition of heavy metals by inhalation of metallic fumes, emphasizing a description of the most used metals in welding, and its relationship with oxidative stress and health effects. [ABSTRACT FROM AUTHOR]

This paper studies the levels of competitiveness and productivity of the Metalworking Sector of the city of Barranquilla, based on the design of an evaluation model for the supply chain of companies belonging to that sector. The model consists of five critical aspects: supply, storage, inventory management, distribution and transport, and reverse logistics. These factors include a set of variables that evaluate the planning, execution, measurement, and control of supply chain management. The model was validated in five companies of the Metalworking Sector of the city of Barranquilla. Solutions for integral logistics practices were established in the procurement processes, taking into account quality standards of processes and security of the supply chain. It is concluded that the sector has presented a great economic growth in the country and it is necessary the optimization and continuous improvement of the productive processes through the monitoring and control of appropriate indicators. [ABSTRACT FROM AUTHOR]

Previous studies of science, technology, engineering, mathematics, and medical (STEMM) professionals have identified a common "mental toolkit" composed of 13 "tools for thinking" that STEMM professionals use in their problem raising and problem solving. The present research surveyed a convenience sample of 225 STEMM professionals to investigate whether these "thinking tools" are correlated with STEMM achievement measured variously as patents filed or licensed, companies founded, number of papers and books published, and copyrights assigned. Some mental skills such as modeling and playing are significantly correlated with patent filings and licenses, and others are correlated with different measures of STEMM achievement. Previous research has also demonstrated that some of these thinking tools, most notably visual thinking skills, can be taught through various arts, crafts, and design (ACD) practices, resulting in significant improvements in STEMM learning outcomes. The present research therefore investigates in the survey pool whether ACD are associated with the same measures of STEMM achievement as thinking tool use. Correlations exist between use of some thinking tools and particular ACD avocations: Modeling and playing are correlated with persistent crafts avocations such as metalworking, woodworking, and mechanics, which are, in turn, significantly correlated with patent production. Most survey participants were explicitly aware of the connections between their ACD avocations; their STEMM work; and the tools, skills, and knowledge derived from the former. We conclude that integrating ACD with STEMM content by means of tools for thinking may be an effective way to achieve improved STEMM learning outcomes. [ABSTRACT FROM AUTHOR]

Manufacturing machine parts of high quality with high productivity and low cost is the most important goal of the production in metalworking industry. For the realization of production goals, single-objective optimization of the machining processes is a good way but multi-objective optimization is the right way. Turning is the most widely used machining process. Turning operation is usually realized through a multi-pass roughing and single-pass finishing. In this paper, multi-objective optimization of turning operation which consists of multi-pass roughing and single-pass finishing AISI 1064 steel with carbide cutting tool, in terms of material removal rate and machining cost, was studied. For multi-pass roughing, optimization problem with two objectives (material removal rate and machining cost), three factors (depth of cut, feed and cutting speed), and five machining constraints (cutting force, torque, cutting power, tool life, and cutting ratio) was studied. For single-pass finishing, optimization problem with two objectives (material removal rate and machining cost), four factors (tool nose radius, depth of cut, feed, and cutting speed), and three machining constraints (surface roughness, tool life, and cutting ratio) was studied. The optimization problem is solved using three techniques: (i) iterative search method, (ii) multi-objective genetic algorithm (MOGA), and (iii) genetic algorithm (GA). With the iterative search method, the values of objectives for all combinations of factor levels were calculated and an optimal solution was selected. With a multi-objective genetic algorithm, a set of optimal solutions named "Pareto optimal set" was defined and an optimal solution was selected. With a genetic algorithm, the optimal solution was determined by using the weighted-sum-type objective function. [ABSTRACT FROM AUTHOR]

Evidence pertaining to Viking Age industry and trade is rarely encountered in the Norwegian archaeological record, although recent evidence suggests that sites of this character are more common than previously thought. Systematic metal detecting and large‐scale geophysical surveys carried out in Øvre Eiker in the southeast of Norway between 2014 and 2016 revealed a multiphase and complex settlement area, consisting of large pits potentially associated with metalworking. The evidence so far points to a site with far‐reaching contemporary connections, where objects were worked and exchanged. This short report aims to present the results from the work undertaken so far and to demonstrate how the complementary use of geophysical surveys and metal detection can add cultural‐historical depth to the site itself and to a little understood aspect of Early Medieval history. [ABSTRACT FROM AUTHOR]

For various industrial manufacturing processes, water-based metalworking fluids (MWFs) are of high relevance due to their cooling and lubricating ability. They commonly form oil-in-water emulsions or solutions and hence their composition and stability is crucial for their performance in the metalworking process. To ensure a long service life of the MWF, intense monitoring is obligatory. However, examination techniques which display comprehensive and precise information about the actual state of the cooling lubricant in use are currently not available. The present study aims at testing the suitability of spectroscopic methods in terms of Fourier transform infrared, Raman, and laser-induced fluorescence spectroscopy for analyzing and monitoring MWFs. It is shown that all three techniques are capable of determining the initial composition, i.e., the ratio of water and concentrate. Fourier transform infrared provides the best performance regarding monitoring the state of the fluid over an extended period of time. The spectral signatures show distinct changes during a five-month service life in a technical environment. [ABSTRACT FROM AUTHOR]

Metalworking fluids (MWFs) used in milling generate oil particles through impaction, action of centrifugal forces and evaporation/condensation mechanisms. The oil particles suspended in the factory atmosphere can affect the health of the labor force. In order to study the emission properties of these oil particles, this work investigates the oil particle emission rate and size distribution during milling using an environmental chamber method. Two commonly used operating modes for MWFs were selected, the minimum quantity lubrication (MQL) mode (40 ml/h) and the cooling mode (1 m³/h). The cooling mode without cutting was studied separately for comparison with the cooling mode with cutting. The results show that the oil particle emission rate in milling ranges from 7.2 to 641 mg/h, and the size distribution ranges from 0.265 to 12.5 µm. Evaporation/condensation is the main mechanism in the MQL mode. The majority of oil particles formed by evaporation/condensation are in the range of 0.265 to 1.8 µm. As the tool rotation speed increases, the particle emission rate increases, while the mass mean diameter (MMD) and the sauter mean diameter (SMD) decrease. Oil particles are mainly generated by the action of centrifugal force in the cooling mode, and mainly distributed in the range of 1.8 to 12.5 µm. The particle emission rate increases with the tool rotation speed, and the particle MMD and SMD increase with the tool rotation speed only in the cooling mode without cutting. The particle emission rate ranging from 1.8 to 12.5 µm, as well as PM5 and PM10, are a polynomial function of the square of tool rotation speed during the cooling mode. The coefficient of determination (R2) is above 0.99. © 2018 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

A developed procedure is used to evaluate the reliability of cutters fitted with replaceable multifaceted plates of oxide VO13, oxide-carbide VOK71, and nitride RKS22ceramics during turning hardened steel 35KhGSA (44 - 48 HRC). The high efficiency of the set of operational characteristics formed and established wear criteria is demonstrated. [ABSTRACT FROM AUTHOR]

In general, the working environment of foundries is bad, compared to other manufacturing industries. To improve this, dust collection facilities are installed or improved. However, they cannot be installed in some factories. Therefore, we attempted to change the sand type from natural silica sand to spherical artificial sand mold with furan resin to improve the working environment. Before switching, we investigated the problems that occur when switching to artificial sand and external shrinkage problems were found. After taking countermeasure against the problem, we changed the sand type. As a result, it was possible to reduce the amount of dust in the working environment, and the control class prescribed by the Ordinance on Prevention of Dust Hazard could be reduced from level 3 to level 2. [ABSTRACT FROM AUTHOR]

It is possible to create value with less environmental impact through the adoption of Lean and Green manufacturing concepts and tools. This paper proposes a Lean-Green model based on the application of the Single Minute Exchange of Die (SMED) combined with Carbon Footprint (CF) to analyze eco-efficiency of a machining center in a case study in Brazil. The novelty of this paper was the proposal of a Lean-Green model based on ecoefficiency indicators to measure performance of production systems toward a cleaner production. The developed Lean-Green model should be used by companies with low-capacity of production due to restrictions of machine availability. The case study was organized in five different scenarios by varying machine tools, workers and workpieces. First, the SMED tool was applied in the setup activities and gains of reduced idle times were up to 88%. CF results were reduced up to 81% after applying the SMED tool on each scenario. Lastly, an eco-efficiency set of indicators were used to combine results of SMED and CF, and results of eco-efficiency were 3% higher even with higher CF values after converting setup saved time into productive time. To achieve such results simple improvements were performed in the machining center, through the standardization of work and the study of time and methods for setup activities, showing that the proposed Lean-Green model could be also adopted by other companies to create value with less impact. [ABSTRACT FROM AUTHOR]

Irradiating a metal wire with an intense femtosecond laser pulse induces a terahertz (THz) surface wave that travels along the wire. Here, the characteristics of the THz surface wave generated by the laser–wire interaction are investigated in detail by using an electro-optical method to determine the dependence of surface wave properties on laser energy and wire diameter. The surface wave is distributed by the Hankel function in the wire radial direction. On the wire surface, the electric field is estimated to be MV/cm. The peak electric field of the surface wave and the conversion efficiency from laser energy to surface wave energy are found to be proportional to the laser energy raised to the power of 0.67 and 0.3, respectively. [ABSTRACT FROM AUTHOR]

Cutting fluids are essential for cutting performance and rust prevention in metalworking processes. Among cutting oils, the usage of water-soluble cutting fluids is increasing rapidly because they afford excellent cooling performance and ensure fire safety. However, water-soluble cutting fluids also offer a favorable environment for the growth of a wide variety of microorganisms. The growth of microorganisms can lead to various problems such as deterioration of the cutting fluids and odor generation. Thus, technologies for purifying the waste of water-soluble cutting fluids are required. In this study, we developed an ozone treatment technology that uses an air DBD plasma system. Furthermore, sterilization experiments were performed with K . pneumoniae , P . aeruginosa , E . coli , and P. vulgaris as representative microorganisms. The system offers the advantages of low power consumption and simple structure. Approximately 1000 ppm of ozone could be stably generated under optimized conditions, and the ozone was injected into the reactor as micro-bubbles for improving reactivity and inactivation rate. The sterilization experiments confirmed that the water-soluble cutting fluid was sterilized by 99.99%. As a result, the turbidity, pH, and odor of water-soluble cutting fluid have been improved. [ABSTRACT FROM AUTHOR]