热处理对Ti_3Al－Nb合金显微组织与拉伸性能的影响

Effect of Heat Treatment on Nicrostructure and Properties of Ti3Al-Nb Alloy

研究了Ｔｉ３Ａｌ－Ｎｂ合金（Ｔｉ－２４Ａｌ－１４Ｎｂ－３Ｖ－０．５Ｍｏ）在不同固溶温度，不同冷却速度以及时效条件下的显微组织与性能之间的关系，结果表明，Ｔｉ３Ａｌ－Ｎｂ合金冷轧板材经α２＋β两相区固溶（９４０℃～１１００℃×１ｈ）水淬处理，其显微组织由初生α２相、β２相和“０”相组成。随着固溶温度的升高，初生α２相逐渐减少，室温力学性能σｂ、σ０．２和δ均相应提高，当初生α２相约为３０％时，可以使合金获得良好的综合性能：σｂ＝９８４，５Ｍｐａ，σ０．２＝７８５．５ＭＰａ，δ＝５．９％。当固溶温度继续升高时，上述性能开始下降。

The relation between the microstruoture and the properties of Ti3Al-Nb alloy (Ti-24Al-14Nb-3V-0.5Mo)at different solution temperatures, different cooling rates and aging conditions were studied. The results show that the microstructure of Ti Al-Nb cold rolled sheet consists of primary B and '0' phases,When the alloy is solution heated at 940℃￣1400℃ for 1 hour and quenched in water.As the solution temperature rises,the primary α2 volume ferction decreases and the yield strength(σ0.2),tensite strength(σb)and elongation(δ)at room temperature increases. When the primary α2 volume fraction approaches 30%,the mechanical properties(σ0.2、σb、δ)are in the best combination,σb=984.5Mpa, 0.2=785.5Mpa,δ=5.9%.With a further increase in the solution temperature,σb、σ0.2 andδdecrease.