铸造技术2025，Vol.46Issue(4)：316-324,9.DOI:10.16410/j.issn1000-8365.2025.4198
Ti-43Al-0.5Re-xCr合金高温变形过程的动态再结晶行为
Dynamic Recrystallization Behavior During Thermal Deformation of Ti-43Al-0.5Re-xCr Alloy
摘要
Abstract
TiAl alloys,novel lightweight,high-temperature metal structural materials,feature low density,high specific strength,and excellent high-temperature performance.However,its narrow hot working window and poor deformation at high temperatures make the formation of alloy components difficult.Adding β-stabilizing elements enhances hot deformation by introducing a disordered β-phase,but the mechanism is unclear.Therefore,Ti-43Al-0.5Re-xCr(x=1,1.5,2,at.％)alloys were used as the research objects,and thermal mechanical compression experiments were conducted at 1 150,1 200 and 1 250 ℃.Flow curves under different conditions were analysed,the effects of temperature and Cr content on the thermal deformation microstructure and dynamic recrystallization were studied,and the microstructural evolution of the Ti-43Al-0.5Re-1.5Cr alloy at 1 200 ℃/0.01 s-1 was clarified.The results indicate that the overall flow stress of the alloy decreases with increasing deformation temperature and Cr content.When the alloys are deformed at 1 150 ℃,many residual lamellar colonies exist in the microstructure that primarily fragment through bending,twisting,and breaking,leading to high deformation resistance.When the alloys are deformed at 1 200 or 1 250℃,most of the alloy microstructure is the α phase,which undergoes continuous dynamic recrystallization,resulting in low deformation resistance.Under deformation conditions of 1 200 ℃,a 0.01 s-1 strain rate,and 40％deformation,the degree of recrystallization in the alloy increases with increasing β phase content.Thus,an increase in the Cr content enhances the content of the β phase in the alloy,which promotes the dynamic recrystallization process of the alloy.In the deformed microstructure of the Ti-43Al-0.5Re-1.5Cr alloy at 1 200 ℃,a strain rate of 0.01 s-1,and 40％deformation,many low angle grain boundaries(LAGBs,2°～15° misorientation)are distributed around the fine β phases,which interconnect to form numerous small-sized subgrains,resulting in the formation of fine recrystallized grains.Thus,the β phase plays a role in refining the recrystallized grains.The microstructures of the Ti-43Al-0.5Re-1.5Cr alloy samples subjected to different strains were studied,revealing their microstructure evolution at 1 200 ℃/0.01 s-1 hot deformation.关键词
TiAl合金/热变形/动态再结晶/Cr含量/组织演变/流变曲线Key words
TiAl alloy/thermal deformation/dynamic recrystallization/Cr content/microstructure evolution/flow curve分类
金属材料引用本文复制引用
邵启航,楚玉东,陈晓飞,卫贝贝,马彪,唐斌..Ti-43Al-0.5Re-xCr合金高温变形过程的动态再结晶行为[J].铸造技术,2025,46(4):316-324,9.基金项目
国家重点研发计划(2021YFB3702605) （2021YFB3702605）
