摘要
以无坩埚感应熔炼超声气体雾化法制备的名义成分为Ti-22Al-24Nb-0.52Mo(原子分数)的预合金粉末为原料,通过包套热等静压工艺制备了粉末冶金Ti2AlNb合金环轧坯料(Ф355mm×Ф200mm×168mm)。Ti2AlNb合金坯料在α2+B2两相区进行单道次环轧,变形量约为30%,变形后环轧坯结构完整,无宏观裂纹。测试了Ti2AlNb合金坯料环轧变形前后的拉伸性能,采用扫描电子显微镜观察变形前后及热处理前后组织的演化。结果表明,粉末冶金Ti2AlNb合金经环轧后,B2相拉长,α2相等轴化,O相板条细化,为典型的双态组织;环轧坯料经过热处理优化后,室温和高温塑性均有明显提升,综合力学性能得到显著改善;变形后O相的体积分数和尺寸变化是影响Ti2AlNb合金高温塑性的重要因素。
Powder metallurgy(PM)ring rolling stock(Ф355 mm×Ф200 mm×168 mm)was made through a hot isostatic pressing route by pre-alloyed Ti-22Al-24Nb-0.5Mo(at.%)powder,which was prepared by electrode induction melting gas atomization(EIGA).The ring billet was ring rolled atα2+B2 region and the total reduction was about 30%.No macrocrack was found in the ring rolled PM Ti 2AlNb billet and a sound rectangular ring blank was obtained.Microstructures of rolled PM Ti 2AlNb after different heat treatments were observed by scanning electron microscopy(SEM),and tensile properties were also tested.Experimental results show that the rolled PM Ti 2AlNb alloy has typical dual-microstructure,B2 phase elongation,α2 phase equiaxialization,O phase lamellar refinement.After the ring rolling,the plasticity at room temperature and high temperature is significantly improved,a good combination of tensile strength,ductility of the ring rolled billet is obtained through an optimized heat treatment.After deformation,the volume fraction and the dimensional change of O phase are important factors of the high temperature plasticity for Ti 2AlNb alloy.
作者
崔潇潇
卢正冠
吴杰
李一平
徐磊
Cui Xiaoxiao;Lu Zhengguan;Wu Jie;Li Yiping;Xu Lei(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《钛工业进展》
CAS
北大核心
2019年第2期25-28,共4页
Titanium Industry Progress
关键词
Ti2AlNb合金
粉末冶金
热等静压
环轧
Ti 2AlNb alloy
powder metallurgy
hot isostatic pressing
ring rolling
