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The influence of cold-rolling directions on the recrystallization texture evolution of pure iron was examined. As-received pure iron sheets were cold-rolled under two different conditions (specimens A and B). Specimen A was cold-rolled in the vertical direction against the cold-rolling direction of the as-received sheet. Specimen B was cold-rolled in the vertical direction against the cold-rolling direction of the as-received sheet, and then in the cold-rolling direction of the as-received sheet. Cold-rolled specimens were heated to each desired temperature before being quenched in water to room temperature (298 ± 2 K). Both cold-rolled specimens showed the development of γ-fiber and 100 orientation. Additionally, γ-fiber formed comparatively more in cold-rolled specimen A, while α-fiber developed comparatively more in cold-rolled specimen B. Strain distribution in cold-rolled specimen A was presumably inhomogeneous, whereas that in cold-rolled specimen B was rather uniform at the macro-scale. The formation of γ-fiber was confirmed in annealed specimen A. In annealed specimen B, however, the recrystallization texture tended to be random, and the formation of α-fiber was observed. Furthermore, the formation of Goss orientation in both annealed specimens was established. Recrystallized ferrite grains with Goss orientation nucleated in high strain regions of cold-rolled specimen. These findings show that by devising the cold-rolling direction, it is possible to discover new types of recrystallization textures.

The accurate calibration of anisotropic yield functions depends on the experimental data generated at diverse stress states. Typically, the calibration experiments for plane-stress anisotropic models involve uniaxial tensile tests in three major orientations with respect to the rolling direction (RD) of the sheet and an equibiaxial tension test, the latter requiring specialized testing apparatus. In this work, the anisotropic plastic behaviour of an aerospace grade AA2024-T3 sheet is investigated using a combination of advanced experimental and analytical techniques. The study presents an expanded approach for yield locus calibration, integrating stack compression and shear testing techniques while requiring only a universal testing machine. By combining these complementary experimental approaches, critical data are obtained at a wide range of stress states, including equal biaxial tension and shear-dominated regimes. In addition, plane-strain tension tests are conducted along RD, 45 degrees to RD, and transverse direction (TD) to provide a more comprehensive assessment of the material’s yield locus. By imposing these critical constraints along diverse stress states, the widely adopted Yld2000-2D anisotropic yield function is calibrated based on an associated flow rule.

This study aims to optimize the stress relief annealing of cold-rolled 5xxx aluminum alloy sheets by examining the effects of annealing temperature on microstructure and mechanical properties. Hot-rolled plates (final rolling temperature: 300 °C) underwent three pre-treatment processes before 70% cold rolling: no treatment (A), 350 °C/2 h (B), and 450 °C/2 h (C). Hardness decreased with increasing annealing temperature, with recrystallization onset near 230 °C. The optimal condition was identified as 200 °C for 1 h, which relieved internal stress while retaining work-hardening strength and promoted only recovery without recrystallization. The microstructure preserved fibrous morphology, second-phase particles, and shear bands at 35–45° to the rolling direction, with fibre width following A > B > C. All H3-state sheets exhibited a ductile–brittle mixed fracture, with plasticity varying among processes. Tensile properties showed significant anisotropy: strength was highest at 0° and lowest at 45°, while elongation peaked at 45° and was lowest at 90°, attributed to activation of the 111〈110〉 slip system. These findings offer practical guidance for industrial processing and performance control of 5xxx alloy sheets.

The effects of cold-rolling reduction (43%, 66%, 87%) and annealing temperature (180 °C-350 °C) on the recrystallization kinetics of 3005 aluminum alloy sheets were investigated through hardness tests and microstructure analyses using EBSD and SEM. The results indicate that cold-rolling elongates the grains along the rolling direction, forming a fibrous structure, which significantly enhances the hardness of the sheets. The recrystallization fraction increases with rising annealing temperature, gradually forming fine, equiaxed recrystallized grains, and recrystallization is nearly completed at 320 °C. As the annealing temperature increases, the hardness of the cold-rolled sheets gradually decreases. Additionally, a greater cold-rolling reduction results in a higher recrystallization fraction at the same annealing temperature. However, the pinning effect of precipitates significantly influences the recrystallization process during high-temperature annealing, leading to the fastest recrystallization rate in samples with a 66% deformation rate during high-temperature annealing.

Modern car bodies are constantly relying higher proportions of high and ultra-high strength steels. In the past, the increase in material strength led to a conflict regarding the complexity of component geometries. Limits of material formability were reached and compromises had to be made in part design. By integrating application-oriented problems into the material development, these limits are expanded with respect to the given requirements. Within the present study, for multiphase steels with a tensile strength ≥1000 MPa, practical laboratory tests are presented and their benefits in press shop application. In this work one dual-phase, one TRIP-steel and a third generation AHSS steel are examined. By using hole expansion tests with a flat bottom punch, combined with insitu strain measurement, the diverse hardening behaviour up to necking is investigated. A Python-script is generated to investigate the strain distribution and evolution in dependency of the rolling direction. Detailed FEM investigations are undertaken to work out the observed phenomena. Furthermore, the applicability concerning material model validation and optimization is discussed for the aim of FEM accuracy improvement.

Bipolar plates (BPPs) in fuel cells are commonly fabricated from ultra-thin metallic sheets, such as commercial-pure Ti (CP-Ti) sheet, with thicknesses ranging from 0.05 to 0.12 mm. During the forming process of BPPs, the material experiences complex loading paths, particularly equi-biaxial tension (EBT) near the fine channel ends. To investigate the plastic deformation behaviour of a 0.10 mm-thick CP-Ti sheet under EBT loading, hydraulic bulge tests were performed with the aid of digital image correlation to measure the strain field and history. Strain hardening curves and evolution of plastic strain were analysed using the ISO method. The results reveal that flow stress under EBT is significantly higher (~1.41 times) than that observed in uniaxial tension along the rolling direction. The strain ratio r b (the ratio of strain in the transverse direction to strain in the rolling direction) of the ultra-thin CP-Ti sheet evolves with increasing plastic work. To model the observed anisotropic, tension-compression asymmetry, a non-associated plasticity model based on CPB06 yield stress function was introduced. Experimental comparison demonstrates that the CPB06 model considering parameter evolution accurately captures the plastic deformation behaviour of ultra-thin CP-Ti sheets.

ZK61 magnesium-alloy plate with high tensile strength and elongation is obtained by combined multipass symmetric hot rolling and asymmetric warm rolling. Deformation history considering varying strain rate obtained from the macro-finite element analysis of the selected passes are introduced into the viscoplastic self-consistent model (VPSC) as initial boundary conditions for macro- multiscale and micro-multiscale coupling analysis. VPSC simulation results show that in the initial stage of rolling deformation, the basal slip is the dominated deformation mode, supplemented by prismatic slip and pyramidal slip. With increased rolling strain, the pyramidal slip presents competitive relationship with basal slip, and the activation amount of 101—1 compression twins is limited. During asymmetric rolling, the basal slip is dominant, followed by the pyramidal slip. Experimental results show that the basal texture is gradually strengthened after symmetric rolling, and grain size is refined due to the activation and recrystallization of twins. Asymmetric rolling makes the basal texture deflect 10° to the rolling direction and further refine the grain size. With the ongoing of symmetric rolling, the mechanical anisotropy of the plate weakens, and the yield strength, tensile strength, and plasticity of the material improves. In particular, after asymmetric rolling, the tensile strength in the RD and TD directions of the plate reaches 391.2 MPa and 398.9 MPa, whereas the elongation reaches 19.8% and 25.5%.

In this work, the compressive creep behaviors of hot-rolled pure Mg (0Y alloy) and various hot-rolled Mg-Y binary alloys (0.15Y, 1.5Y, 4.5Y, 7.5Y, and 10.5Y alloys) at 523 K were systematically studied under various applied stresses. These alloys all had an average grain size of ~100 μm. The loading directions were parallel to the rolling direction (RD), transverse direction (TD), and normal direction (ND). The creep behaviors were shown to exhibit an obvious dependence on the loading direction in the 0Y, 0.15Y, 1.5Y, and 4.5Y alloys. The creep resistance had a sequence of ND > TD ≥ RD in these alloys. The creep anisotropy of the alloys was caused by 〈a〉 dislocation cross-slipping from the basal plane to the prismatic plane and 101¯2 twinning dominating the creep along the RD and TD, while dislocation climb and pyramidal 〈c + a〉 slip prevailed along the ND. Compared to the 0Y, 0.15Y, and 1.5Y alloys, the more random basal texture in the 4.5Y alloy weakened the cross-slip and twinning along the RD and TD and triggered cross-slip along the ND, resulting in decreased creep anisotropy. For the 7.5Y and 10.5Y alloys, an approximate creep isotropy due to cross-slip and pyramidal 〈c + a〉 slip dominated the creep along all three loading directions. Moreover, compared to the 0Y alloy, the creep resistance was found to be slightly increased in the 0.15Y alloy and significantly increased with increasing the Y content above 1.5 wt pct, which can be attributed to solution strengthening and the promoted pyramidal 〈c + a〉 dislocations collaboratively increasing the creep resistance. The improved hindering effect on twinning also helped to increase the creep resistance along the RD and TD. In addition, dynamic precipitation strengthening assisted the increment of creep resistance in the 10.5Y alloy. Thus, the addition of concentrated Y in Mg alloys is a valid solution to eliminate the compressive creep anisotropy and simultaneously enhance the creep resistance.

Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation, or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation. It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment, without complex geometry or a control module. In this work, we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated, continuous rolling motions under constant light irradiation. The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient. The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion. The hydrogel robots can reach a rolling speed of 1.27 mm·s −1 on a horizonal surface and even climb a ramp of 18° at a speed of 0.57 mm·s −1 in an aqueous environment. Furthermore, the hydrogel robots can overcome an obstacle, with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions. This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.

Three kinds of 6061 aluminum alloy thin-walled tubes rolled by Pilger cold rolling mill and three-high rolling mill were taken as the research objects. EBSD, SEM and tensile test were used to analyze the microstructure, texture and mechanical properties of the tubes under natural aging. The results show that the grain size near the mandrel in the tube wall is larger, and the grain near the roll is smaller. The grains on the transverse section are elongated and elongated along the rolling direction. Under the large deformation of 84 % ~ 87 %, the main textures of thin-walled 6061 aluminum alloy tube are V texture, Brass texture, γ fiber texture and H texture. Under natural aging, the tensile strength and yield strength of 6061 aluminum alloy tube gradually increase with time, and remain basically unchanged after 60 days. The higher processing deformation, the higher tensile strength of tube, the lower elongation.