激光熔化沉积Ti60合金、TiC_p/Ti60复合材料的高温拉伸持久寿命及断裂过程  

High-Temperature Tensile Rupture Life and Fracture Procedure of Laser Direct Deposited Ti60 Alloy and TiC_p/Ti60 Composites

作　　者：孙景超[1] 张永忠[1] 宫新勇[1] 刘铭坤[1] 

机构地区：[1]北京有色金属研究总院复合材料中心,北京100088

出　　处：《中国激光》2012年第1期65-70,共6页Chinese Journal of Lasers

基　　金：国家973计划(2011CB606305);国家自然科学基金(50871023)资助课题

摘　　要：通过激光熔化沉积工艺制备出Ti60合金和质量分数为5%的TiCp/Ti60复合材料,分析比较了两种材料的微观组织及高温(600℃)拉伸持久性能。结果表明,所沉积TiCp/Ti60复合材料中初生TiC呈树枝晶分布于原始β晶界,共晶TiC呈颗粒状分布于α-Ti板条间,TiC的存在导致基体组织细化。TiCp/Ti60复合材料较基体合金具有更加优异的高温(600℃)拉伸持久寿命,其高温拉伸持久断裂过程为:增强体与基体界面脱粘、α-Ti/β-Ti的界面处微孔形核、长大、横向扩展及连接,最终导致复合材料的失效。Ti60 alloy and TiCp（mass fraction of 5%）/Ti60 titanium matrix composites are fabricated by laser direct deposition process.The microstructure and tensile rupture life under 600 ℃ are investigated and compared.The results indicate that,for laser direct deposited TiCp/Ti60 composites,primary TiC appears as dendrites and distributes at the original β grain boundary,and the eutectic TiC appears as particulate and distributes between α laths.The existence of TiC results in refinement of the matrix.Compared with the Ti60 alloy,TiCp/Ti60 composite exhibits a superior rupture life and creep resistance under 600 ℃.The creep rupture of the composite is primarily initiated by a mixture of interface debonding between TiC and the matrix and interface voiding between α-Ti and β-Ti,which is followed by the ductile failure through the matrix.

关 键 词：激光技术 激光熔化沉积 Ti60合金 TiCp/Ti60复合材料 持久寿命 

分 类 号：TN249[电子电信—物理电子学] TF124[冶金工程—粉末冶金]