CAJ | 학술논문

在中温550℃对Ti-25 at．%Nb合金进行ECAP挤压4道次处理后,合金的微观组织为拉长晶粒,不能得到细小的等轴晶粒。挤压温度降低至400℃, ECAP挤压后合金的晶粒可得到明显细化,其中,经过2道次ECAP挤压后,微观组织以拉长态的晶粒为主,局部区域出现晶粒尺寸约为500 nm的细小等轴晶粒；在400℃经过ECAP挤压4道次,组织进一步细化为200~300 nm等轴细小晶粒。
재중온550℃대Ti-25 at．%Nb합금진행ECAP제압4도차처리후,합금적미관조직위랍장정립,불능득도세소적등축정립。제압온도강저지400℃, ECAP제압후합금적정립가득도명현세화,기중,경과2도차ECAP제압후,미관조직이랍장태적정립위주,국부구역출현정립척촌약위500 nm적세소등축정립；재400℃경과ECAP제압4도차,조직진일보세화위200~300 nm등축세소정립。
The paper studied microstructure of Ti-25at.% Nb al oy. The results showed that grain structure was elongated but without obtaining equiaxed UFG after 4 passes ECAP at 550℃; grain refinement became obvious as process temperature decreased to 400℃, among which, most grains were elongated, and some equiaxed UFG were observed with a grain size of 500 nm after two passes ECAP;equiaxed UFG were obtained after 4 passes ECAP at 400 ℃ with a grain size of 200~300 nm.