应变对两相区固溶处理Ti-55531合金室温压缩变形机制的影响

Effect of Strain on Room Temperature Compression Deformation Mechanism of Ti-55531 Alloy after Two-phase Solution Treatment

使用Gleeble3800热模拟试验机和6.3MN锻造模拟试验机对两相区固溶处理Ti-55531合金进行室温压缩变形实验,运用SEM、XRD和TEM分析变形组织,研究应变对两相区固溶处理Ti-55531合金室温压缩变形机制的影响。结果表明,两相区固溶处理Ti-55531合金组织由初生αp相和残余βr相组成,αp相的硬度低于βr相;当室温压缩工程应变量为8%~10%时,合金位错主要集中于αp相中;随着应变的增加,αp相中的位错密度增大,当工程应变量增大到20%时,大量位错在αp相与βr相的相界面处聚集,αp相内形成严重的位错塞积和位错缠结,βr相中滑移系开动的数量也逐渐增多;当工程应变量增大到30%时,βr相中也出现了位错塞积和位错缠结;应变量继续增大,当工程应变量增大到60%时,等轴的初生αp相沿变形方向被拉长,同时αp相和βr相中均出现大量位错胞。

Room temperature compression deformation experiments of Ti-55531 alloy after two-phase solution treatment were carried out using Gleeble3800 thermal simulation test machine and 6.3 MN forging simulator.SEM,XRD and TEM were used to characterize the deformed microstructure.The effect was studied of strain on room temperature compression deformation mechanism of Ti-55531 alloy after two-phase solution treatment.The results show that the microstructure of Ti-55531 alloy after two-phase solution treatment consists of primaryαp phase and residualβr phase,andαp phase has lower hardness thanβr phase.When the engineering strain of room temperature compression is 8%~10%,the dislocation of the alloy is mainly concentrated inα_p phase.As the strain increases,the dislocation density inα_p phase increases.When the engineering strain increases to 20%,a large number of dislocations are clustered atαp/βr phase boundary,serious dislocation accumulation and dislocation entanglement are formed inαp phase,and the number of activated slip systems inβr phase is also gradually increased.When the engineering strain increases to 30%,dislocation accumulation and dislocation entanglement also occur inβr phase.When the strain continues to increase and the engineering strain increases to 60%,the equiaxed primaryαp phase is elongated along the deformation direction,and a large number of dislocation cells appear in bothαp phase andβr phase.