β锻造工艺对TC17钛合金显微组织的影响

Effect of β Forging Process on Microstructure of TC17 Titanium Alloy

摘要:

通过对Φ100 mm×150 mm TC17钛合金棒材进行镦粗试验,研究了β锻造工艺对其微观组织形貌的影响。结果表明:变形量和变形速率对TC17钛合金显微组织有显著的影响。当变形速率为0.1 mm/s时,晶界α相容易被破碎,变形量越大,破碎越严重,且越容易球化,80%变形量时α相的球化率达到80%。当变形速率为2 mm/s时,β晶粒容易发生动态再结晶,变形量越大,再结晶体积分数越高,80%变形量时β相的再结晶体积分数为50%。晶界α相发生球化对变形量和变形速率均较为苛刻,仅在变形量为80%、变形速率为0.1 mm/s时大量晶界α相发生了球化。此外,相比变形量,β再结晶数量对变形速率更加敏感。

关键词:TC17钛合金;;β锻造;;变形量;;变形速率;;再结晶

Abstract:

The effect of β forging process on microstructure was studied by compressing test for Φ100 mm×150 mm TC17 titanium alloy bar.The results show that the height reduction and the deformation rate have a significant effect on the microstructure of TC17 titanium alloy.When the deformation rate is 0.1 mm/s,the grain boundary α phase is easily broken.And the larger the deformation is,the easier grain boundary α phases are to be globularized,which has been severely broken.The percent of globularized α phases is 80% at the height reduction of 80% and deformation rate of 0.1 mm/s.When the deformation rate is 2 mm/s,the β grains are prone to dynamic recrystallization.And the larger the deformation is,the higher the recrystallization volume fraction is.The recrystallization volume fraction of β grain is 50% at the height reduction of 80% and deformation rate of 2 mm/s.The grain boundary a phase can be globularized only in some strict conditions.The a phases are globularized only at the height reduction of 80% and deformation rate of 0.1 mm/s in this study.In addition,the amount of β grain recrystallization is more sensitive to the deformation rate than the height reduction.

Key words:TC17 titanium alloy;β forging;height reduction;deformation rate;recrystallization