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The tensile behavior of Sn–Bi–Cu and Sn–Bi–Ni alloys has been widely investigated. Reportedly, the addition of small amounts of a third element can refine the microstructures of the eutectic Sn-58mass% Bi solder and improve its ductility. However, the superplasticity mechanism of Sn-based alloys has not been clearly established. Therefore, in this study, the effects of Sb and Zn addition on the microstructures and tensile properties of Sn–Bi-based alloys were investigated. The alloys were subjected to tensile tests under various strain rates and temperatures. We found that Zn- and Sb-added Sn–Bi-based alloys demonstrated superplastic deformation at high temperatures and low strain rates. Sb addition significantly affected the elongation of the Sn–Bi–Sb alloys because the metal dissolves in both the primary Sn phase and the eutectic Sn–Bi matrix. The segregation of Zn and formation of needle-like Zn particles at the eutectic Sn–Bi phase boundary affected the superplastic deformation of the alloys. The deformation of the Sn–40Bi-based alloys at high temperatures and low strain rates led to dynamic recovery, dynamic recrystallization, and/or grain boundary slip because of the accumulation of voids.

The aim of the paper was to investigate the mechanical parameters of two different natural fiber composite rings using the tensile and split disk tests. The tests are carried out with various thickness specimens (1.5 mm, 2.00 mm and 3.00 mm) of two different natural fibers (Kenaf and Kevlar). Hoop tensile and axial tensile properties of the samples were identified, and the effect of filament winding dispersion on the hoop tensile and longitudinal properties of the designated composites were also attained. Minor rise in the hoop and longitudinal tensile properties of rings created with Kenaf natural fiber was observed and contrasted to those designed with Kevlar natural glass fiber. The design analysis was accomplished in accordance to the American Society for Testing and Materials ASTM D 2290 standard. Split-disk analysis of Kenaf and Kevlar natural composite rings were modelled and simulated using the finite element method and analysis (Ansys 16.0). A reasonable understanding was achieved by the natural composites through the finite element simulation and the results of the two different fibers.

To apply the duplex type low-carbon medium-manganese steel to the hot/warm-forging and -stamping products, the influence of cooling process routes immediately after intercritical annealing such as air-cooling (AC) and isothermal transformation (IT) processes on the impact toughness of 0.2%C-1.5%Si-5%Mn (in mass %) duplex type medium-Mn (D-MMn) steel was investigated. Moreover the microstructural and tensile properties were also investigated. The AC process increased the volume fraction of reverted austenite but decreased the thermal and mechanical stability in the D-MMn steel, compared to the IT process. The AC process increased the tensile strength but decreased the total elongation. The Charpy V-notch impact value and ductile-brittle transition temperature were deteriorated by the AC process, compared to the IT process. This deterioration of the impact toughness was mainly related to the reverted austenite characteristics and fracture mode.

To develop a cost-effective shape memory alloy fiber-reinforced engineered cementitious composite (SMAF-ECC) with excellent mechanical properties, polypropylene (PP) fibers were used to partially replace polyvinyl alcohol (PVA) fibers to prepare the ECC matrix, and superelastic shape memory alloy fibers (SMAFs) were incorporated to fabricate a novel SMAF-ECC. Uniaxial tensile tests were systematically performed to characterize the tensile mechanical properties of the composites, focusing on the effects of SMAF volume content and diameter. The results indicate that the optimal base ECC mix proportion is 0.8 vol.% PP fibers and 1.2 vol.% PVA fibers, achieving an ultimate tensile strain of 4.88% (only a 4.69% reduction compared to pure PVA-ECC) while significantly reducing material cost without sacrificing superior ductility. SMAF volume content and diameter notably influence the tensile performance of SMAF-ECC, with the specimen containing 0.2 mm diameter SMAFs at 0.2 vol.% exhibiting the best performance: initial cracking stress, ultimate tensile stress, and ultimate tensile strain are enhanced by 16.79%, 20.85%, and 2.87%, respectively, compared to pure ECC. This study provides a theoretical basis and parametric guidance for the engineering popularization and application of cost-effective SMAF-ECCs.

Wire and arc additive manufacture (WAAM), as an emerging and promising technology of metal additive manufacturing, it lacks of experimental works to clarify the feature of geometrical configuration, microstructure and tensile properties, which can be used for further evaluating whether the as-deposited part can be used directly, and providing design reference for structure optimization. Taking 5A06 aluminum alloy additive manufacturing for example, in this paper, the geometric limitation and tensile property criteria are characterized using experimental method. The minimum angle and curvature radius that can be made by WAAM are 20° and 10 mm when the layer width is 7.2 mm. It shows isotropy when loading in build direction and perpendicular one. When loading in the direction of parallel and perpendicular to texture orientation, the tensile properties are anisotropic. The difference between them is 22 MPa.

Selective laser melting (SLM) technology is one of the commonly used technologies in metal additive manufacturing. In this study, AlSi10Mg powder was used as the raw material to form 9 groups of specimens with different combinations of laser power and scanning speeds through the SLM process. Tensile testing, density testing, XRD, LSCM, SEM and EDS analysis were performed to indicate the effects of laser power and scanning speed on density, microstructure and tensile properties of SLM AlSi10Mg alloys were studied. The results show that increasing the laser power and reducing the scanning speed within a certain range can improve the continuity of the formed specimens, and significantly reduce the porosity. For parameter combinations with the same energy density, when laser power and scanning speed are simultaneously increased, the laser power has a dominant effect on increasing the temperature inside the molten pool, leading to more uniform melting of the powder. This can improve both the density and internal porosity distribution, and furthermore produce more precise and uniform microstructures. The relative density and tensile strength of the specimens formed at 225 W/1625 mm/s are 3.6 and 16.5% higher than 135 W/975 mm/s, respectively.

Fused filament fabrication-based 3D printing technology is considered a new approach for manufacturing fiber-reinforced polymer parts due to proper control over fiber position and orientation within the polymer matrix. In this study, the performance of 3D printed composites of Onyx reinforced with continuous glass, Kevlar, and carbon fibers has been examined. The Markforged Mark Two 3D printer was used to develop tensile test specimens as per ASTM D638 standard. An L9 array of the Taguchi design of experiment is employed for experimentation. The effect of fiber type, fiber volume, fiber isotropic angle, and fiber concentric rings on tensile properties has been studied. After analysis of the results, it is observed that tensile properties are significantly improved on reinforcement with continuous fiber. The maximum tensile strength of 369 MPa and maximum tensile modulus of 3.4 GPa were achieved with 45% carbon fiber reinforced at 0° isotropic angle and three numbers of concentric rings in each layer. Measurement was also carried out to assess the dimensional quality of the test specimens and found as precise. Scanning electron microscopy indicates the presence of voids at multiple locations around the microfibers, causing a reduction in the tensile properties. The individual micro-fibers were seen as misaligned, mainly in the case of Kevlar fiber. The present work may guide the professionals working with continuous fiber-reinforced 3D printed polymer composites in selecting appropriate process conditions for their specific needs.

The Ni-coated red mud/Al-5.4Cu-0.7Mg-0.6Ag-based composite materials were fabricated by gravity casting, and the Ni-coated red mud particles were prepared via chemical deposition. The effect of the content of nickel-coated red mud particles on the microstructures and high-temperature tensile properties of these composites was analyzed. The results demonstrate that the addition of trace amounts of Ni-coated red mud particles effectively refines the Ω precipitates, reducing their average size to approximately 185.06 nm, while simultaneously improving the high-temperature tensile strength. The higher tensile strength is attained with 172.2 MPa at 350 °C when the content of Ni-coated red mud particle is 1 wt%. However, when the content of red mud reaches 1.5 wt%, the phenomenon of red mud particle agglomeration begins to occur. Although the role of refining the Ω phase still exists, the agglomeration areas are prone to forming crack sources, which in turn reduces the high-temperature tensile properties of the material.

A novel non-magnetic Fe-21Cr-15Ni-5Mn-2Mo austenitic stainless steel with high strength and plasticity has been developed. The microstructure and liquid helium temperature (4.2 K) tensile properties of the top and bottom samples of large-size forged flat steel after solution treatment at 1090 °C were investigated. The results showed that the average grain size of the bottom sample (48.0 ± 6.7 μm) was smaller than that of the top sample (58.8 ± 15.3 μm), and the MX precipitates and Z phases were distributed in the matrix of the samples. The 4.2 K strengths of the samples at the top and bottom were high, and large amounts of annealing twin boundaries played a certain role in strengthening. After cryogenic tensile testing, large amounts of deformation twins, stacking faults, and dislocations were generated inside the austenite grains of both samples, which helped the material to obtain higher plasticity and strength. The top and bottom samples possessed excellent synergies of strength and plasticity at 4.2 K, and the 4.2 K tensile properties of the top sample were as follows: ultimate tensile strength (UTS) of 1850 MPa, yield strength (YS) of 1363 MPa, and elongation (EL) of 26%. The tested steel is thus believed to meet the requirements of combined excellent strength and plasticity within a deep cryogenic environment, and it would be a promising material candidate for manufacturing superconducting coil cases to serve in new generation fusion engineering.

In this research, we systematically investigated equiatomic CoCrFeNi and CoCrFeMnNi high-entropy alloys (HEAs). Both of these HEA systems are single-phase, face-centered-cubic (FCC) structures. Specifically, we examined the tensile response in as-cast quaternary CoCrFeNi and quinary CoCrFeMnNi HEAs at room temperature. Compared to CoCrFeNi HEA, the elongation of CoCrFeMnNi HEA was 14% lower, but the yield strength and ultimate tensile strength were increased by 17% and 6%, respectively. The direct real-time evolution of structural defects during uniaxial straining was acquired via in situ neutron-diffraction measurements. The dominant microstructures underlying plastic deformation mechanisms at each deformation stage in as-cast CoCrFeNi and CoCrFeMnNi HEAs were revealed using the Convolutional Multiple Whole Profile (CMWP) software for peak-profile fitting. The possible mechanisms are reported.