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Stainless steels have many practical applications requiring various mechanical or chemical demands in the working environment. By optimizing a device used in mechanical experiments for torsional loading, several cylindrical samples were tested (both ends twisted with the same torque value in opposite directions) of 316L stainless steel (SS) to evaluate changes in the structural, chemical, and mechanical characteristics. Initially, the experimental samples were pre-loaded by tension in the elastic range (6%) and then subjected to torsion (772°) at different rates: 5, 10, and 20 mm/min. The experimental sequence consisted of a combined loading protocol with an initial tensile test followed by a subsequent torsional test. Two reference tests were performed by fracturing the samples in both torsion and tension to determine the mechanical strength parameters. The macro- and microstructural evolution of the samples as a function of the torsional degree was followed by scanning electron microscopy. The microhardness modification of the material was observed because of the strain (the microhardness variation from the center of the disk sample to the edge was also monitored). Structurally, all samples showed grain size changes because of torsional/compressive deformation zones and an increase in the degree of grain boundary misorientation. From the tensile and torsional behaviors of 316L SS and the structural results obtained, it was concluded that these materials are suitable for complex stress states in the elasto-plastic range through tensile and torsion. A reduction in Young’s modulus of up to four times the initial value at medium and high stress rates was observed when complex stresses were applied.

Laser Powder Directed Energy Deposition (LP-DED) can produce thin-wall features on the order of 1 mm. These features are essential for large structures operating in extreme environments such as regeneratively cooled nozzles and heat exchangers, which often make use of refractory metals. In this work, the mechanical behavior of LP-DED C103 was investigated via quasi-static tensile testing and low cycle fatigue (LCF) testing. The effects of vacuum stress relief (SR) and hot isostatic pressing (HIP) heat treatments were investigated for specimens in the vertical and horizontal build orientations during tensile testing. The AB and SR properties were lower than literature values for wrought and laser powder bed fusion (L-PBF) bulk components but higher than electron beam powder bed fusion (EB-PBF). The application of a HIP cycle improved strength by 7% and ductility by 27% past the initial as-built condition. Fracture images reveal that interlayer stress concentration sites are responsible for fracture in specimens in the vertical orientation. Meanwhile, fracture in the horizontal specimens mainly propagates at a slanted angle typical of plane stress conditions. The LCF results show cycles to failure ranging from 100 cycles to 8000 cycles for max strain levels of 2% and 0.5%, respectively. Fractography on the fatigue specimens reveals an increasing propagation zone as max strain levels are increased. The impact of these findings and future work are discussed in detail.

Aluminium alloys have a wide range of applications, mainly due to their advantageous strength-to-weight ratio, denoted as specific strength and corrosion resistance. In recent decades, there has been a notable surge in the usage of recycled alloys, attributed to their reduced production costs and emissions. One of the conditions for secondary production is the optimal sorting of used scrap. Once the aluminium scrap has been melted, it is tough to reduce the content of the various additives. Copper is the primary alloying element in some aluminium alloys, which leads to an increased amount of copper in the aluminium scrap. Therefore, it is important to investigate its effect on the properties of aluminium alloys in which it is not commonly present. For this reason, this paper is concerned with the influence of copper on the microstructure and properties of the secondary aluminium alloy AlZn10Si8Mg. Specifically, it compares two melts of self-hardening AlZn10Si8Mg alloys differing in copper content (0.019% and 1.72%). A complex quantitative and metallographic analysis by optical and electron microscopy has been performed. Mechanical properties were investigated by tensile test, Brinell hardness, and Vickers microhardness measurements. The corrosion resistance of the individual melts was verified by the Audi test.

In this study, the most effective application method of guayule resin and its effects on termite and fungal decay biological performances of wood strand-based (WSB) panels were explored. Southern yellow pine (Pinus spp. L.) wood strands were mixed with phenol formaldehyde (PF) resin to a target resin content of 5.00% and hot-pressed to manufacture the control WSB panels. For the in-situ process, a guayule resin solution was prepared and sprayed on the wood strands immediately after spraying the PF resin to a target content of 5.00%. For brushing and spraying methods, a sub-set of the control panel specimens were further brushed or sprayed with guayule resin solution on all surfaces. To understand the effects of guayule on durability, specimens cut from control and treated panels were subjected to termite resistance and fungal degradation soil block tests. The in-situ specimens with 5.00% guayule were subjected to tensile, internal bond, water absorption, and thickness swelling tests to find out whether guayule affects the mechanical performance of WSB panels. The results showed that in-situ treatment resulted in a significant reduction in the mechanical properties of wood stand-based panels. The sprayed technique resulted in more durable panels, as the mass loss was 2.21% for termites and 3.24% for fungi specimens, which decreased by 76.66% and 80.86%, respectively, when compared to the WSB controls.

Engineered Geopolymer Composites (EGCs), known for their excellent tensile properties and lower carbon emissions, have gained widespread attention in the field of fiber-reinforced concrete. However, the high cost of high-performance synthetic fibers, a crucial component of EGCs, limits their practical engineering applications. In this study, by using low-cost PP fibers hybridized with PE fibers and adjusting the fly ash/ground granulated blast furnace slag (FA/GGBS) ratio, cost-effective, high-performing hybrid PE/PP-reinforced engineered geopolymer composites (H-EGCs) were developed. This study conducted axial compressive and tensile tests on H-EGCs with different FA/GGBS ratios (7:3, 6:4, and 5:5) and PP fiber replacement ratios (0%, 25%, 50%, 75%, and 100%), investigated the influence of FA/GGBS and PP fiber replacement ratio on static mechanical behavior, and evaluated the economic and environmental benefits based on mechanical performance indicators. The result indicated that the compressive strength of H-EGCs can reach 120 MPa when the FA/GGBS ratio is 5:5; however, an increase in FA/GGBS and PP fiber replacement ratio leads to a loss in compressive strength and elastic modulus. The incorporation of PP fibers in moderate amounts enhances ultimate tensile strain by reducing crack control ability, and the maximum tensile deformation capacity (7.82–9.66%) was obtained for H-EGCs with a PP fiber replacement ratio of 50%. The optimal economic and environmental benefits of H-EGCs are observed when the FA/GGBS ratio is 5:5 and the PP fiber replacement ratio is set at 50%.

To meet the complex and diverse demands for low-stress mechanical measurements of fabrics and other flexible materials, two integrated multidimensional force sensors with the same structure but different ranges were explored. They can support both rapid and precise low-noise, high-precision, low-cost, easy-to-use, reliable, and intelligent solutions for the complex measurement of fabric mechanics. Having analysed the mechanical relationship of the parallel beam theory, and considering the specific requirements of fabric measurement, a novel multi-dimensional force sensor is designed, capable of measuring tensile, shear, and buckling properties. Finite element analysis is used to simulate the mechanical performance of this sensor for fabric-loading/unloading measurement, and the sensitivity of the mechanical quantity transfer, the amount of sensor deformation, the stress distribution, and the degree of inter-dimensional coupling have been investigated and verified. The basis for subsequent digital processing is achieved by a low-offset, low-temperature-drift, low-power-consumption analogue front end, 24-bit ADC circuit, and signal conditioning electronics, suitable for the measurement of fabric mechanics under low stress, which is like the end-user requirements. The sensor information channel is supported by a host microcontroller with a DSP and a floating-point processing instruction set. Information processing is performed in time-sharing with the support of a multitasking real-time operating system. The purpose of designing this sensor is to facilitate the development of a new testing instrument, which will adopt the advances of current instruments whilst eliminating their shortcomings.

Stitched filaments are known to modify the mechanical properties of glass-fiber-reinforced polymers 2D (GFRPs 2D), so studying the effect on mechanical properties is underway to determine the critical variables involved. This research focuses on the study of the tensile strength effect of stitched low-density Barkley FBA BGQS15-15 nylon monofilament on biaxial E-Glass Saertex 830 g/m2 (+/−45°) cured with Polyester Sypol Resin 8086 CCP using a vacuum infusion process. Four specimens were made with longitudinal distances between the stitched reinforcements of 0.5, 1.0, 1.5, and 2.0 cm, respectively. Tensile strength tests based on standard ASTM D3039 were performed to study how stitching can affect toughness, Young’s modulus, deformation, ultimate strength, and yield strength. The results indicated that the stitching increases Young’s modulus up to 99.2%, UTS is increased by up to +3.14%, deformation decreases by up to −41.66%, and toughness decreases by up to −36.89%. Although the stitching’s main function is to increase interlaminar resistance, it also induces the formation of stress concentrations by the new threads, and premature failure in the matrix was shown.

Today, especially in many fields that require structural durability, such as the aerospace and automotive industries, there has been a need to use different bonding techniques separately or together in order to use materials together with different mechanical properties. In this study, stress and damage analysis of single lap joints, bonding and bolt-bonding metal/composite joints under tensile loads were performed. The nine kinds of single lap joint models in different combinations (bonded, bolted and bolt-bonded) were prepared by using acrylic adhesive (Acrytron 1E1) and 100-25-3 mm in size; AZ91/AZ91, AZ91-carbon fiber and carbon fiber-carbon fiber plates. Some comparisons were carried out by examining the stresses and deformations that occur in joint models exposed to tensile and 4-point bending tests. As a result of the tensile test, it was determined that the highest maximum tensile stress occurred in AZ91-CF bolt-bonded samples. In the four-point bending test, the maximum shear force value was determined in the CF-CF bolted-bonded samples.

X80 steel is extensively used in hydrogen environments and is susceptible to hydrogen embrittlement (HE). This paper studied the hydrogen-induced cracking (HIC) behavior in the coarse-grained heat-affected zone (CGHAZ) of X80 steel welds, through applying in situ hydrogen-charging tensile experiments, hydrogen permeation experiments, and various surface analysis techniques. It is shown that a few hydrogen atoms can significantly decrease a material’s elongation and reduction of area. When the heat input (HI) was 29.2 kJ/cm, the material had minor sensitivity to hydrogen embrittlement. The tensile fractures were ductile without hydrogen. However, the fracture surface exhibited brittle fracture with hydrogen. With increased HI, the HE fracture showed a transition of intergranular fracture→intergranular and transgranular mixed fracture→transgranular fracture. In the presence of hydrogen, the grain boundaries of elongated strips were prone to the formation of intergranular cracks under a tension load, and the hydrogen embrittlement resistance of the bulk lath bainite (LB) was weak. The hydrogen embrittlement susceptibility of pure granular bainite (GB) was lower. Fine LB and GB composite structures could remarkably inhibit intergranular cracks, giving the steel a superior resistance to hydrogen embrittlement.

In order to study the strengthening effect of Mg–X (X = Zn, Ag) alloys, solid solution structures of Mg54, Mg53X1 and Mg52X2 (X = Zn, Ag) with atomic contents of 1.8 at.% and 3.7 at.% were established, respectively. The structural stability, tensile properties and electronic properties were investigated by first-principles simulation. The calculated results of cohesive energies show that all solid solution structures were stable under different tensile strains, and Mg52Ag2 had the best stability. The results of tensile tests show that Zn and Ag atoms promoted the Mg-based alloy’s yield strength and tensile strength. In addition, through comparative analyses, we have demonstrated that the tensile property of Mg-based alloys was also affected by solid solubility. Finally, the electronic density of states (DOS) and electron density difference of several solid solution structures were analyzed.

It is important to understand the mechanical properties of diamond-like carbon (DLC) for use not only in frictionand wear-resistant coatings, but also in vibration reduction and damping increase at the layer interfaces. However, the mechanical properties of DLC are influenced by the working temperature and its density, and the applications of DLC as coatings are limited. In this work, we systematically studied the deformation behaviors of DLC under different temperatures and densities using compression and tensile testing of DLC by molecular dynamics (MD) methods. In our simulation results, the values of tensile stress and compressive stress decreased and tensile strain and compressive strain increased as the temperature increased from 300 K to 900 K during both tensile and compressive processes, indicating that the tensile stress and tensile strain depend on the temperature. During the tensile simulation, Young’s modulus of DLC models with different densities had a different sensitivity to the increase in temperature, and the DLC model with a high density was more sensitive than that with a low density, which was not seen in the compression process. We conclude that the Csp3-Csp2 transition leads to tensile deformation, while the Csp2-Csp3 transition and relative slip dominate compressive deformation.

This paper investigated the micromechanical behavior of different 6H-SiC/Al systems during the uniaxial tensile loading by using molecular dynamics simulations. The results showed that the interface models responded diversely to the tensile stress when the four low-index surfaces of the Al were used as the variables of the joint surfaces. In terms of their stress–strain properties, the SiC(0001)/Al(001) models exhibited the highest tensile strength and the smallest elongation, while the other models produced certain deformations to relieve the excessive strain, thus increasing the elongation. The SiC(0001)/Al(110) models exhibited the largest elongations among all the models. From the aspect of their deformation characteristics, the SiC(0001)/Al(001) model performed almost no plastic deformation and dislocations during the tensile process. The deformation of the SiC(0001)/Al(110) model was dominated by the slip of the 1/6 Shockley partial dislocations, which contributed to the intersecting stacking faults in the model. The SiC(0001)/Al(111) model produced a large number of dislocations under the tensile loading. Dislocation entanglement was also found in the model. Meanwhile, a unique defect structure consisting of three 1/6 stair-rod dislocations and three stacking faults were found in the model. The plastic deformation in the SiC(0001)/Al(112) interface model was restricted by the L-C lock and was carried out along the 1/6 stair-rod dislocations’ direction. These results reveal the interfacial micromechanical behaviors of the 6H-SiC/Al composites and demonstrate the complexity of the deformation systems of the interfaces under stress.

The type of diet that a horse consumes is one of the most important factors determining the mineral profile and tensile strength of its hooves, so the quality and nutritional value of the supplied feed are fundamental to achieving satisfactory hoof quality. The objective of this study was to compare the differences in the mineral concentrations of sodium (Na), potassium (K), magnesium (Mg), zinc (Zn), and Iron (Fe) between two diets, namely silage and a commercial concentrate, using atomic absorption spectrometry and to determine which led to higher increases in the hoof tensile strength of horses consuming these diets. Thirty-two Spanish horses were randomly divided into two groups, where the diet of the horses in group 1 was silage oat hay, and that of the horses in group 2 was a commercial concentrate and oat hay. Both diets were provided for 12 months. The hoof tensile strength was then measured using an Instron universal testing machine. Mg and Fe levels were higher (p < 0.05) in the silage than in the commercial concentrate, and hoof Mg, Zn, K, and tensile strength were also influenced by the hormonal stage (p < 0.05). The type of diet directly affected the hoof Mg, Zn, K, Na, and tensile strength (p < 0.05), which Mg, K and Na were higher in horses fed with concentrate. It was found that for each unit of Zn (μg/g and Na (μg/g)), in the hoof, the tensile strength is affected by −0.10 N/mm2 and −0.003 N/mm2, respectively for each mineral.

In the present study, the stress corrosion cracking (SCC) behavior of ECAP Al5083 alloy was investigated in air as well as in 3.5 % NaCl solution using the slow strain rate tensile test (SSRT). The characteristics of grain boundary precipitates (GBPs), specifically the microchemistry of the SCC behavior of Al5083 alloys, both in “as-received” condition and when deformed by the ECAP process, were examined. The correlations between the SCC resistance and GBP microchemistry were examined. A microstructural evaluation was performed using an optical microscope. SCC tests were carried out using a universal tensile testing machine and the fracture surfaces were studied using scanning electron microscopy (SEM). A strain rate of 1×10−6 s−1 was applied for the SSRT. As the passes increased, the SCC susceptibility of the fine-grained ECAP Al5083 alloy also increased. Moreover, higher ultimate tensile strength and greater elongation were observed. This was due to grain refinement, high-density separations, and the expanded extent of high-density dislocations instigated by severe plastic deformation. Due to the high strength and elongation, the failure analysis showed a ductile mode of fracture. Electron backscattering diffraction (EBSD) analysis was performed to determine more clearly the nature of cracking. EBSD analysis showed that the crack propagation occurred in both transgranular and intergranular modes.

The incorporation of materials that were formally regarded as agricultural wastes into polymeric matrix has drawn the attention of many researchers in recent years. This research focused on reinforcing high-density polyethylene (HDPE) matrix with treated jute fiber (JF)/oil palm pressed fruit fibers (OPPFF) at varying weight proportions. JF and OPPFF were cut to 2.5 mm length and were chemically treated thereafter with 1 M and 1.5 M sodium hydroxide solution respectively. The composites were produced using the compression molding technique. The morphological characterization of the fibers and composites for untreated and treated samples was studied with the aid of a scanning electron microscope (SEM). Tensile and flexural properties of the produced composite samples were also determined. From the result, the surface morphology of the fiber after treatment showed that there was obvious exposure of the fiber surface and removal of impurities as this influenced the microstructure of the composites and in turn the tensile and flexural properties. Hence, it was observed that 20 wt.% treated jute fiber addition shows the most significant enhancements in terms of tensile and flexural properties. The study exposed the effect of surface modification of JF/OPPF hybridization on HDPE matrix composite.

Thin-walled Inconel 625 sheet metal was sectioned into tensile specimens, plastically strained, and then heat treated. Specimens were pulled to a targeted strain, unloaded, and then subjected to one of two heat treatments with the goal of restoring the full ductility and total plastic strain capability of the material. Post-heat treatment tensile testing was performed at room temperature to evaluate the heat treatment efficacy and then followed by hardness and microstructural analysis. The results showed the amount of material recovery was affected by the initial amount of plastic strain imparted to the tensile specimen before heat treatment. Although recrystallization was not observed, grains did elongate in the load direction, and the Kernel average misorientation (KAM) increased with heat treatment. Furthermore, specimens prestrained to 40% and heat treated at 980 °C successfully recovered 88% of pre-heat treatment strain capability prior to fracturing.

Fused Filament Fabrication (FFF) is a promising technology for production of fiber-reinforced composite parts with complex geometries. Continuous Fiber Reinforced Additively Manufactured (CFRAM) parts are becoming more prominent due to their mechanical performance, light weight, and recyclability. CFRAM components are lighter, yet they are strong materials with a wide range of potential applications in the automotive industry, aerospace, medical tools, and sports goods. The wide range of applications of these novel materials justifies the need to study their properties. Tensile is one of the most important tests to evaluate the mechanical performance of CFRAM parts. In this paper, a comprehensive study is conducted on tensile properties of CFRAM components. The composite parts are printed using a dual nozzle 3D printing machine and their tensile performance is investigated. Furthermore, the effect of fiber type, fiber content, infill density, infill pattern, and layer thickness on tensile properties was studied. Nylon was used as the matrix and Carbon fiber (CF), fiberglass (FG), and Kevlar were used as reinforcing agents. Microstructural analysis was conducted to investigate the fracture mechanism, internal morphology, interlayer adhesion, and the printing quality of specimens. Finally, a comparative study is conducted on the price and printing time of CFRAM parts. It is observed that fiber inclusion increases the tensile strength up to 2200%; moreover, increasing the fiber content improves the tensile performance of composite. The results obtained demonstrate that CF-reinforced parts have better performance compared to FG and Kevlar-reinforced components. The results show that CFRAM parts have potential to replace metals and conventional composites for engineering applications like the automobile industry.

This article presents a novel method to grow a high-quality compressive-strain Ge epilayer on Si using the selective epitaxial growth (SEG) applying the RPCVD technique. The procedures are composed of a global growth of Ge layer on Si followed by a planarization using CMP as initial process steps. The growth parameters of the Ge layer were carefully optimized and after cycle-annealing treatments, the threading dislocation density (TDD) was reduced to 3 × 107 cm−2. As a result of this process, a tensile strain of 0.25% was induced, whereas the RMS value was as low as 0.81 nm. Later, these substrates were covered by an oxide layer and patterned to create trenches for selective epitaxy growth (SEG) of the Ge layer. In these structures, a type of compressive strain was formed in the SEG Ge top layer. The strain amount was −0.34%; meanwhile, the TDD and RMS surface roughness were 2 × 106 cm−2 and 0.68 nm, respectively. HRXRD and TEM results also verified the existence of compressive strain in selectively grown Ge layer. In contrast to the tensile strained Ge layer (globally grown), enhanced PL intensity by a factor of more than 2 is partially due to the improved material quality. The significantly high PL intensity is attributed to the improved crystalline quality of the selectively grown Ge layer. The change in direct bandgap energy of PL was observed, owing to the compressive strain introduced. Hall measurement shows that a selectively grown Ge layer possesses room temperature hole mobility up to 375 cm2/Vs, which is approximately 3 times larger than that of the Ge (132 cm2/Vs). Our work offers fundamental guidance for the growth of high-quality and compressive strain Ge epilayer on Si for future Ge-based optoelectronics integration applications.

The development of membrane technology from biopolymer for water filtration has received a great deal of attention from researchers and scientists, owing to the growing awareness of environmental protection. The present investigation is aimed at producing poly(D-lactic acid) (PDLA) membranes, incorporated with nanocrystalline cellulose (NCC) and cellulose nanowhisker (CNW) at different loadings of 1 wt.% (PDNC-I, PDNW-I) and 2 wt.% (PDNC-II PDNW-II). From morphological characterization, it was evident that the nanocellulose particles induced pore formation within structure of the membrane. Furthermore, the greater surface reactivity of CNW particles facilitates in enhancing the surface wettability of membranes due to increased hydrophilicity. In addition, both thermal and mechanical properties for all nanocellulose filled membranes under investigation demonstrated significant improvement, particularly for PDNW-I-based membranes, which showed improvement in both aspects. The membrane of PDNW-I presented water permeability of 41.92 L/m2h, when applied under a pressure range of 0.1–0.5 MPa. The investigation clearly demonstrates that CNWs-filled PDLA membranes fabricated for this investigation have a very high potential to be utilized for water filtration purpose in the future.

This paper deals with the dielectric and mechanical characterizations of polyacrylonitrile (PAN)-aligned electrospun nanofiber mats. A two factor three level full factorial experiment is conducted to understand the effect of various parameters on dielectric and mechanical responses. These responses are recorded against randomly oriented and aligned nanofiber mats. Improved properties of electrospun mats have applications in the field of energy storage and nanocomposite reinforcement. Dielectric and mechanical characterizations of PAN mats are vital, as the aligned electrospun mats were found to be useful in advanced energy and mechanical reinforcement applications. Therefore, it is paramount to understand the effects of system parameters to these properties. The design of experiment (DoE) includes two factors and three level full factorial experiments with concentrations of PAN solutions at 8 wt.%, 9 wt.%, and 10 wt.%, and speed of the rotating mandrel (collector) at 3 volt (V), 4 V, and 5 V inputs. The electric field intensity used in the experiment is 1 kV/cm. DoE is conducted to understand the nonlinear interactions of parameters to these responses. The dielectric and mechanical characterizations of 8 wt.%, 9 wt.%, and 10 wt.% with different speeds for the original and improved systems are discussed. It was observed that at 9 wt.% and at all mandrel speeds, the dielectric and tensile properties are optimum.

The high strength of twinning-induced plasticity (TWIP) steels makes them vulnerable to the hydrogen embrittlement (HE) phenomenon, thereby limiting their potential applications. This study suggests inducing a graded grain structure (GGS) in a Fe-17Mn-0.8C TWIP steel through shot peening and subsequent heat treatment to solve the problem. The microstructures and fracture surfaces of GGS TWIP steel were compared with those of conventionally manufactured TWIP steel possessing a uniform grain structure (UGS). Compared with the conventional UGS TWIP steel, GGS steel showed similar tensile properties with a yield strength of 310 MPa, tensile strength of 1060 MPa, and elongation-to-failure of 135%. It also exhibited moderately enhanced low-cycle fatigue (LCF) resistance in terms of fatigue life (8196 cycles to failure) compared with the UGS steel (7201 cycles). Furthermore, GGS TWIP steel exhibited a marked improvement in HE resistance, both in the monotonic (by a slow-strain-rate test) and cyclic deformation modes (by the LCF test) in a hydrogen environment. A relatively fine-grained (d = 15.6 μm) surficial area enhanced the HE resistance by inhibiting hydrogen penetration and decreasing twin density, while the coarse-grained (d = 74.6 μm) interior promoted the LCF resistance by suppressing crack growth.

The research elaborates on the mechanical properties at the Al (111)/6H-SiC (0001) interface based on the density functional theory. Because of the difference in atom category at the interface of 6H-SiC (0001), it takes the C-terminated interface and Si-terminated interface into account. As indicated by the gross energy computing results at the two interfaces, the C-terminated Al (111)/6H-SiC (0001) interface demonstrates a greater adhesion force than the Si-terminated counterpart. Throughout detailed analysis on the bonding mechanism, surface hybridization and charge transfer at the Al (111)/6H-SiC (0001) reaction interface, the research reveals its strong covalent characteristics. According to the comparative study on the ideal tensile strength and general stacking fault energy at varying cleavage surfaces, a conclusion can be fitly reached that the fracture at the Al (111)/6H-SiC (0001) interface is easily seen in Al-Al bonds in the Al matrix instead of C(Si)-Al bonds at the interface. Despite the greater adhesion energy of the C-Al bond than the Si-Al bond, Al-Al bonds close to the C-terminated Al (111)/6H-SiC (0001) interface easily fracture due to the low ideal tensile strength.

Metal additive manufacturing (AM) has gained much attention in recent years due to its advantages including geometric freedom and design complexity, appropriate for a wide range of potential industrial applications. However, conventional metal AM methods have high-cost barriers due to the initial cost of the capital equipment, support, and maintenance, etc. This study presents a low-cost metal material extrusion technology as a prospective alternative to the production of metallic parts in additive manufacturing. The filaments used consist of copper, bronze, stainless steel, high carbon iron, and aluminum powders in a polylactic acid matrix. Using the proposed fabrication technology, test specimens were built by extruding metal/polymer composite filaments, which were then sintered in an open-air furnace to produce solid metallic parts. In this research, the mechanical and thermal properties of the built parts are examined using tensile tests, thermogravimetric, thermomechanical and microstructural analysis.

In order to expand the mechanical and physical capabilities of 3D-printed structures fabricated via commercially available 3D printers, nanocomposite and microcomposite filaments were produced via melt extrusion, 3D-printed and evaluated. The scope of this work is to fabricate physically and mechanically improved nanocomposites or microcomposites for direct commercial or industrial implementation while enriching the existing literature with the methodology applied. Zinc Oxide nanoparticles (ZnO nano) and Zinc Oxide micro-sized particles (ZnO micro) were dispersed, in various concentrations, in Acrylonitrile Butadiene Styrene (ABS) matrices and printable filament of ~1.75mm was extruded. The composite filaments were employed in a commercial 3D printer for tensile and flexion specimens’ production, according to international standards. Results showed a 14% increase in the tensile strength at 5% wt. concentration in both nanocomposite and microcomposite materials, when compared to pure ABS specimens. Furthermore, a 15.3% increase in the flexural strength was found in 0.5% wt. for ABS/ZnO nano, while an increase of 17% was found on 5% wt. ABS/ZnO micro. Comparing the two composites, it was found that the ABS/ZnO microcomposite structures had higher overall mechanical strength over ABS/ZnO nanostructures.

We used selective laser melting (SLM) Inconel 718 (coded AS) to carry out three heat treatment processes: (1) double aging (coded A), (2) solid solution + A (coded SA), (3) homogenization + SA (coded HSA) in order to investigate the effects of microstructure changes and tensile strength enhancement on erosion resistance. The as-SLM IN718 and three heat-treated specimens were subjected to clarify the effects of erosion-induced phase transformation on tensile mechanical properties. All heat-treated specimens showed better erosion resistance than as-SLM IN718 did at all impact angles. The as-SLM IN718 and the three heat-treated specimens produced new γ′ phase or metal-oxide via particle erosion, which increased the surface hardness of the material. The thickness of the erosion affected zone is 200 μm, which is the main cause of tensile embrittlement.

The influence of a polypropylene fiber on the tensile properties of a cement-polymer based thin spray-on liner (TSL) was investigated in this study. Two different contents of fiber were added to the liner, yielding two TSL groups. Tensile tests were performed (in accordance with the ASTM D638 standard) on the two groups of specimens as well as the control group at 1, 7, 14, and 28-day curing. The test result verified the large plasticity and low elastic modulus of the TSL compared with the fiber. SEM examination revealed that fibers lying parallel to the load direction ruptured or were pulled out from the matrix, which was beneficial to the tensile strength, but detrimental to the elongation because of their high stiffness. Other fibers lying perpendicular with the load direction were detrimental to both tensile strength and elongation through aggravating the propagation of the cracks. The tensile strength was improved by fiber incorporation, while the elongation was reduced at all curing. The influence of fibers on tensile toughness was uncertain since tensile toughness depended on strength as well as deformity.

In this study, powder bed fusion Ti-6Al-4V alloy flake was subjected to heat treatment at 800 °C for 4 h for inducing the complete transformation of the α’ phase into the α+β phases. An erosion experiment with 450 µm mean particle diameter of Al2O3 particles at a 90° impact on both the as- powder bed fusion (PBF) Ti-6Al-4V and the 4-h 800 °C heat-treated specimens to clarify the particle erosion-induced phase transformation behavior and its effect on mechanical properties. Particle erosion-induced phase transformation to the α phase was observed on both the as-PBF Ti-6Al-4V and the heat-treated specimens. It brought about a sequential formation from the surface to the bottom: (1) a surface softened zone, (2) a hardened zone, and (3) a hardness stabilization zone. The as-PBF Ti-6Al-4V was positively eroded by erosion particles, decreasing strength and ductility. In the case of the heat-treated specimens, we found decreased strength yet an increased ductility.

In the present study, AZ41 and AZ51 alloys were fabricated using disintegrated melt deposition technique followed by hot extrusion. AZ41/Yttria and AZ51/Yttria composites were prepared using 0.6 wt% yttria nano particles in the alloys using the same fabrication technique. From the tensile test results, both strengths (yield and tensile) and ductility were improved in AZ51 when compared to AZ41. In comparison with its alloy counterparts, the yield and tensile strengths were enhanced while maintaining the same ductility in AZ41/Yttria composite, but comparable strengths with decreased ductility were observed in AZ51/Yttria composite. Under compressive loading, an improvement in strengths with similar ductility was observed in AZ51 when compared to AZ41. The best combination of strengths and ductility was observed in AZ51/Yttria composites from compression test results. The obtained mechanical properties are correlated with the microstructure observations.

The modern high strength steel plates have an excellent combination of strength and toughness based on micro-alloying and complex microstructure. Retaining this combination of properties in the weld zone is a major challenge for applications in high-demanding structural construction. This work investigates the weldability of three different modern high strength steel plates, with a thickness of 8 mm. Two of the test materials were produced by a thermo-mechanically controlled process (TMCP) and one by a quenching and tempering method (Q&T). Two-passes MAG (metal active gas) welding was used with four different heat inputs. The tests implemented on all the materials included tensile, hardness profiles (HV5), Charpy-V impact toughness tests, and microstructure analysis using scanning electron microscope (SEM). For one of the TMCP steels, some extended tests were conducted to define how the tensile properties change along the weld line. These tests included tensile tests with digital image correlation (DIC), and 3-point bending tests. The most notable differences in mechanical properties of the welds between the materials were observed in Charpy-V impact toughness tests, mostly at the vicinity of the fusion line, with the Q&T steel more prone to embrittlement of the heat affected zone (HAZ) than the TMCP steels. Microstructural analysis revealed carbide concentration combined with coarse bainitic structures in HAZ of Q&T steel, explaining the more severe embrittlement. During the tensile tests, the DIC measurements have shown a strain localization in the softest region of the HAZ. Increasing the heat input resulted in earlier localization of the strain and less maximum strength. The tensile properties along the weld line were investigated in all welding conditions, and the results emphasize relevant and systematic differences of the yield strength at the transient zones near the start and end of the weld compared with the intermediate stationary domain.

Friction stir welding (FSW) has enjoyed great success in joining aluminum alloys. As lightweight structures are designed in higher numbers, it is only natural that FSW is being explored to join dissimilar aluminum alloys. The use of different aluminum alloy combinations in applications offers the combined benefit of cost and performance in the same component. This review focuses on the application of FSW in dissimilar aluminum alloy combinations in order to disseminate research this topic. The review details published works on FSWed dissimilar aluminum alloys. The detailed summary of literature lists welding parameters for the different aluminum alloy combinations. Furthermore, auxiliary welding parameters such as positioning of the alloy, tool rotation speed, welding speed and tool geometry are discussed. Microstructural features together with joint mechanical properties, like hardness and tensile strength measurements, are presented. At the end, new directions for the joining of dissimilar aluminum alloy combinations should guide further research to extend as well as to improve the process, which is expected to raise further interest on the topic.

Currently, research on structural health monitoring systems is focused on direct integration of the system into a component or structure. The latter results in a so-called smart structure. One example of a smart structure is a component with integrated strain sensing for continuous load monitoring. Additive manufacturing, or 3D printing, now also enables such integration of functions inside components. As a proof-of-concept, the Fused Deposition Modeling (FDM) technique was used to integrate a strain sensing element inside polymer (ABS) tensile test samples. The strain sensing element consisted of a closed capillary filled with a fluid and connected to an externally mounted pressure sensor. The volumetric deformation of the integrated capillary resulted in pressure changes in the fluid. The obtained pressure measurements during tensile testing are reported in this paper and compared to state-of-the-art extensometer measurements. The sensitivity of the 3D printed pressure-based strain sensor is primarily a function of the compressibility of the capillary fluid. Air- and watertightness are of critical importance for the proper functioning of the 3D printed pressure-based strain sensor. Therefore, the best after-treatment procedure was selected on basis of a comparative analysis. The obtained pressure measurements are linear with respect to the extensometer readings, and the uncertainty on the strain measurement of a capillary filled with water (incompressible fluid) is ±3.1 µstrain, which is approximately three times less sensitive than conventional strain gauges (±1 µstrain), but 32 times more sensitive than the same sensor based on air (compressible fluid) (±101 µstrain).