In order to elucidate the microstructure evolution and silicide precipitation behavior during high-temperature deformation,TiB reinforced titanium matrix composites were subjected to isothermal hot compression at 950...In order to elucidate the microstructure evolution and silicide precipitation behavior during high-temperature deformation,TiB reinforced titanium matrix composites were subjected to isothermal hot compression at 950℃,strain rate of 0.05 s^(−1) and employing different strains of 0.04,0.40,0.70 and 1.00.The results show that with the increase of strain,a decrease in the content,dynamic recrystallization of theαphase and the vertical distribution of TiB along the compression axis lead to stress stability.Meantime,continuous dynamic recrystallization reduces the orientation difference of the primaryαphase,which weakens the texture strength of the matrix.The recrystallization mechanisms are strain-induced grain boundary migration and particle stimulated nucleation by TiB.The silicide of Ti_(6)Si_(3) is mainly distributed at the interface of TiB andαphase.The precipitation of silicide is affected by element diffusion,and TiB whisker accelerates the precipitation behavior of silicide by hindering the movement of dislocations and providing nucleation particles.展开更多
Asymmetric lowered-temperature rolling was applied to the fabrication of fine-grained ZK60 magnesium alloy sheet with weak basal texture along the rolling direction(RD).The results showed that multi-pass lowered-tempe...Asymmetric lowered-temperature rolling was applied to the fabrication of fine-grained ZK60 magnesium alloy sheet with weak basal texture along the rolling direction(RD).The results showed that multi-pass lowered-temperature rolling could significantly improve the microstructure homogeneity and refine the grain size.Meanwhile,a fiber texture along the transverse direction(TD)gradually developed during rolling process.Importantly,the shear deformation along the RD made the c-axis of basal plane rotate to the RD,weakening the basal texture along this direction.Influenced by such microstructure variation,the yield strength along the TD continuously increased due to the successive grain refinement and the increased activation of prismatic slips,whereas the uniform elongation decreased owing to the decline of strain hardening ability.In contrast,the continuous weakening of basal texture along the RD increased the activation of soft basal slips,greatly offsetting the strengthening effect contributed by grain refinement and thereby causing the slight decrease of yield strength.展开更多
基金supported by National Natural Science Foundation of China(Nos.51975146,52205344)the Natural Science Foundation of Shandong Province,China(No.ZR2020QE171)+1 种基金the Key Research and Development Plan in Shandong Province,China(No.2019JZZY010364)the National Defense Basic Scientific Research of China(No.JCK2018603C017)。
基金financial supports from the National Natural Science Foundation of China (No. 51871184)the Natural Science Foundation of Shandong Province, China (No. ZR2019MEM037)+1 种基金the Zhoucun School-City Integration Development Plan, China (No. 2020ZCXCZH03)the School-city Integration Development Project of Zibo, China (No. 2019ZBXC022)。
文摘In order to elucidate the microstructure evolution and silicide precipitation behavior during high-temperature deformation,TiB reinforced titanium matrix composites were subjected to isothermal hot compression at 950℃,strain rate of 0.05 s^(−1) and employing different strains of 0.04,0.40,0.70 and 1.00.The results show that with the increase of strain,a decrease in the content,dynamic recrystallization of theαphase and the vertical distribution of TiB along the compression axis lead to stress stability.Meantime,continuous dynamic recrystallization reduces the orientation difference of the primaryαphase,which weakens the texture strength of the matrix.The recrystallization mechanisms are strain-induced grain boundary migration and particle stimulated nucleation by TiB.The silicide of Ti_(6)Si_(3) is mainly distributed at the interface of TiB andαphase.The precipitation of silicide is affected by element diffusion,and TiB whisker accelerates the precipitation behavior of silicide by hindering the movement of dislocations and providing nucleation particles.
基金supported by the National Natural Science Foundation of China (Nos. 51975146, 51801192, 52205344)the Natural Science Foundation of Shandong Province, China (No. ZR2020QE171)+1 种基金Key Research and Development Plan in Shandong Province, China (No. 2019JZZY010364)the National Defense Basic Scientific Research of China (No. JCK2018603C017)
文摘Asymmetric lowered-temperature rolling was applied to the fabrication of fine-grained ZK60 magnesium alloy sheet with weak basal texture along the rolling direction(RD).The results showed that multi-pass lowered-temperature rolling could significantly improve the microstructure homogeneity and refine the grain size.Meanwhile,a fiber texture along the transverse direction(TD)gradually developed during rolling process.Importantly,the shear deformation along the RD made the c-axis of basal plane rotate to the RD,weakening the basal texture along this direction.Influenced by such microstructure variation,the yield strength along the TD continuously increased due to the successive grain refinement and the increased activation of prismatic slips,whereas the uniform elongation decreased owing to the decline of strain hardening ability.In contrast,the continuous weakening of basal texture along the RD increased the activation of soft basal slips,greatly offsetting the strengthening effect contributed by grain refinement and thereby causing the slight decrease of yield strength.
