粉末冶金Ti-22Al-25Nb合金的放电等离子烧结工艺数值模拟与实验研究  

Numerical Simulation and Experimental Study on SPS Processes for a Powder Metallurgy Ti-22Al-25Nb Alloy

作　　者：贾建波[1] 刘文超[1] 刘海亮 鹿超 徐岩[1,2] 杨越 骆俊廷[1] JIA Jianbo;LIU Wenchao;LIU Hailiang;LU Chao;XU Yan;YANG Yue;LUO Junting(Education Ministry Key Laboratory of Advanced Forging&Stamping Technology and Science,Yanshan University,Qinhuangdao,Hebei,066004;National Engineering Research Center for Equipment and Technology of C.S.R,Yanshan University,Qinhuangdao,Hebei,066004)

机构地区：[1]燕山大学先进锻压成形技术与科学教育部重点实验室,秦皇岛066004 [2]燕山大学国家冷轧板带装备及工艺工程技术研究中心,秦皇岛066004

出　　处：《中国机械工程》2018年第19期2377-2383,共7页China Mechanical Engineering

基　　金：河北省自然科学基金资助项目(E2016203157);秦皇岛市科学与技术基金资助项目(E201602A008);燕山大学博士基金资助项目(B936)

摘　　要：选用Ti-22Al-25Nb预合金粉末为实验初始原料,采用放电等离子烧结工艺(SPS)制备组织致密的粉末冶金Ti-22Al-25Nb合金。采用MSC.Marc有限元软件对SPS过程中粉末的致密化过程进行了数值模拟,分析了烧结温度、保温时间和烧结压力对粉末致密化过程的影响,揭示了粉末相对密度随烧结温度、保温时间和烧结压力的变化规律。根据模拟结果,在950~1 200℃温度区间、50 MPa烧结压力和10~20 min保温时间的条件下,完成系列SPS烧结实验,制备获得Ti-22Al-25Nb合金。系统分析了50 MPa/10 min烧结条件下温度对Ti-22Al-25Nb合金的相对密度、显微组织和力学性能的影响,揭示了烧结合金的断裂机制。实验结果表明烧结合金在950℃/50 MPa/10 min条件下具有最优的综合力学性能,延伸率和屈服强度分别达到8.14%和691.04 MPa。A Ti-22Al-25Nb alloy with dense microstructure was prepared by using SPS method from pre-alloy powders.The densification of the powders during the SPS processes was simulated nu-merically by using the finite element software MSC.Marc.The effects of sintering temperature,holding time and sintering pressure on the densification processes of the Ti-22Al-25Nb powders were analyzed,respectively.The evolutions of relative density varying with sintering temperature,holding time and sin-tering pressure were revealed,respectively.Based on the results of simulation,the temperature range of 950~1 200℃,50 MPa pressure and 10~20 min holding time were utilized in a series of sintering experi-ments to fabricate the Ti-22Al-25Nb alloys.The effects of temperature on the relative density,micro-structure evolution and mechanics property of Ti-22Al-25Nb alloy at 50 MPa/10 min were systemati-cally revealed.In addition,the fracture mechanism of the alloys sintered at different temperatures was re-vealed,respectively.The results show that the alloys sintered at 950℃/50 MPa/10 min exhibit a better mechanics property with the elongation of 8.14%and the yield stress of 691.04 MPa.

关 键 词：Ti-22Al-25Nb预合金粉末 放电等离子烧结 相对密度 断裂机制 

分 类 号：TG146.2[一般工业技术—材料科学与工程]