置氢Ti-6Al-4V合金组织与室温变形行为的相关性

应用压缩实验研究置氢Ti-6Al-4V合金的室温力学行为,采用OM、SEM分析了氢对钛合金组织的影响和断口形貌特征,探讨了置氢钛合金组织和室温变形行为之间的相关性.结果表明:氢的固溶强化作用使置氢Ti-6Al-4V合金硬化效应增加,但适量的氢可以显著降低其压缩屈服强度和弹性模量,且断裂时发生的变形量增加,此时合金组织为α+β的双态组织,当合金中产生粗大的β晶粒时,断裂时发生的变形量显著降低;氢的加入促进了合金中斜方马氏体α″的生成;置氢Ti-6Al-4V合金的室温压缩断口为延性沿晶断裂或脆性沿晶断裂和解理型穿晶断裂两种断裂方式的混合断口.

Correlation between microstructure and room-temperature deformation behavior of the hydrogenated Ti-6Al-4V alloy

The room temperature behavior of the hydrogenated Ti-6Al-4V alloy was investigated by compression test ences of hydrogen on the microstructure and the morphology of fracture were analyzed. The correlation between room-temperature plasticity of the hydrogenated Ti-6Al-4V alloy was explored. The results show that the hardening effect of the hy-drogenated Ti-6Al-4V alloy is enhanced due to the solution strengthening function of hydrogen, but the addition of appropriate hydrogen to the Ti-6Al-4V alloy can dramatically decrease the yield strength and elastic modulus and can increase the compression ratio of the alloy with the α + β binary microstructure. The compression ratio wiU fall largely when there are coarse β grains in the alloy. Moreover, the addition of hydrogen can promote the generation of orthorhombic martensite α″. The fracture of the hydrogenated Ti-6Al-4V alloy generally displays as compounded one of ductile or brittle intercrystalline fracture and transcrystalline fracture.