Jinru Luo

Influence of thermomechanical processing on microstructure, texture evolution and mechanical properties of Al–Mg–Si–Cu alloy sheets

Abstract Influence of thermomechanical processing on the microstructure, texture evolution and mechanical properties of Al–Mg–Si–Cu alloy sheets was studied systematically. The quite weak mechanical properties anisotropy was obtained in the alloy sheet through thermomechanical processing optimizing. The highly elongated microstructure is the main structure for the hot or cold-rolled alloy sheets. H {001}〈110〉 and E {111}〈110〉 are the main texture components in the surface layer of hot-rolled sheet, while β -fibre is dominant in quarter and center layers. Compared with the hot-rolled sheet, the intensities of β -fibre components are higher after the first cold rolling, but H {001}〈110〉 component in the surface layer decreases greatly. Almost no deformation texture can be observed after intermediate annealing. And β -fibre becomes the main texture again after the final cold rolling. With the reduction of the thickness, the through-thickness texture gradients become much weaker. The through-thickness recrystallization texture in the solution treated sample only has cube ND {001}〈310〉 component. The relationship among thermomechanical processing, microstructure, texture and mechanical properties was analyzed.

Microstructure and mechanical properties of a basal textured AZ31 magnesium alloy cryorolled at liquid-nitrogen temperature

A strongly basal textured AZ31 magnesium alloy were cryorolled at liquid-nitrogen temperature at various strains. The microstructure and texture of the rolled sheets have been investigated using electron backscatter diffraction (EBSD) and X-ray diffraction. The microstructural and textural evolutions of the AZ31 magnesium alloy during cryorolling have been discussed. A lot of twins were observed in the rolled sheets. The influence of strain on the twin types and variant selection during cryorolling for the magnesium alloy has been discussed quantitatively based on the orientation data collected using EBSD. The influence of the twins on the microstructural and textural evolutions for the AZ31 magnesium alloy during cryorolling has also been discussed. The mechanical properties of the cryorolled sheets were tested by uniaxial tensile tests at the ambient temperature with a strain rate 10-3s-1 in the tensile direction respectively along the rolling and transverse directions of the rolled sheets. The relationships between the mechanical properties and microstructure of the cryorolled sheets have been discussed in the present work. The active twinning during rolling at that cryogenic temperature has been found to play an important role in influencing the microstructure, texture, as well as the mechanical properties of the AZ31 magnesium alloy.

Twinning Behavior of a Basal Textured Commercially Pure Titanium Alloy TA2 at Ambient and Cryogenic Temperatures

Twinning greatly affects the microstructure and mechanical performance of titanium alloys. The twinning behavior of a basal textured commercially pure titanium TA2 plates rolled to 4% reduction at the ambient and cryogenic temperatures has been investigated. Microstructures of the rolled samples were investigated by optical microscope (OM) and the twinning analysis was carried out based on orientation data collected by electron back-scatter diffraction (EBSD). {1122} contraction twins, {1124} contraction twins and {1012} extension twins have been observed. Twinning mode activity varied with rolling temperature. Twinning is considered as the dominant deformation mechanism during rolling at both temperatures for the strain condition. Larger proportion of grains activates twinning during cryorolling, and greater number and more diverse types of twins are observed; manifestly related to the suppression of dislocation slips at the cryogenic temperature. {1122} contraction twins are the dominate twin type within samples rolled at both temperatures. Several {1124} contraction twins are observed in the cryorolled sample while there are only a few in the sample rolled at room temperature. A few tiny {1012} twins have been identified in both samples. {1124} contraction twins are preferentially activated at cryogenic deformation temperature and the {1012} extension twins may result in local strain accommodation.

Microstructure and mechanical properties of cryorolled AZ31 magnesium alloy sheets with different initial textures

AZ31 magnesium alloy sheets with different strong textures were cryorolled at the liquid-nitrogen temperature to the strain of 4% and 8%. The microstructure and texture of the rolled sheets were investigated via scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). The mechanical properties of the sheets were tested through in-plane uniaxial tensile tests at ambient temperature. The tensile stress was exerted in the rolling direction (RD) and transverse directions (TD). The microstructural and textural evolutions of the alloy during cryorolling were investigated. Due to active twining during rolling, the initial texture significantly influenced the microstructural and textural evolutions of the rolled sheets. A

Effect of heating rate on mechanical property, microstructure and texture evolution of Al–Mg–Si–Cu alloy during solution treatment

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Effect of solution time on microstructure, texture and mechanical properties of Al–Mg–Si–Cu alloys

extension twin was found as the dominated twin-type in the cryorolled samples. After cryogenic rolling, the ductility of the samples decreased while the strength increased. Twinning also played an important role in explaining the mechanical differences between the rolled samples with different initial textures. The samples were significantly strengthened by the high stored energy accumulated from cryorolling.