摘要
以SLM成形TC4钛合金为研究对象,通过观察金相形貌和进行能谱分析,研究了固溶时效热处理过程中激光选区熔化(SLM)成形TC4(Ti6Al4V)钛合金组织的演变机理。结果表明:经800℃/2 h/FC热处理后,沉积态SLM成形TC4钛合金中马氏体已完全分解。经950℃/2 h/WQ热处理后,亚稳态的β基体上生成了针状马氏体α',合金元素(如Al、V)有明显扩散,较多的V元素迁移到β基体中,形成过饱和β固溶体。在随后的时效过程中,马氏体α'发生分解,形成了片状α相,晶界出现α相的形核长大,形成了断续的晶界α相(αGB)。次生α相(αS)从亚稳态的过饱和β基体中析出,颗粒状β相围绕着αS相弥散分布,形成了β转变组织。试样的整体组织由断续αGB、球状α、网篮状α及β转变组织组成。
The microstructural evolution of TC4(Ti6Al4V)alloy fabricated by selective laser melting(SLM)was studied by observing the microstructure of metallography and energy spectrum analysis.The results show that the martensite in the SLM-fabricated TC4 alloy is resolved completely after 800℃/2 h/FC heat treatment.After heat treatment at 950℃/2 h/WQ for 2 h,the needle marteniteα'is generated on the metastableβmatrix,alloy elements(e.g.,Al,V)have obvious diffusion,and more V element migrate into theβmatrix,the oversaturatedβsolid solids are formed.In the process of aging heat treatment,martensiteα'is decomposed to lamellarα.The shaped nucleus of the crystal boundary emergence phase grows up to form a continuous crystal boundaryαphase(αGB).The secondaryαphase(αS)emerges from the metastable supersaturatedβmatrix,and the granularβphase spreads aroundαS phase,formingβtransition microstructure.The overall microstructure of the sample consists of intermittentαGB,spheralityα,basketweaveαandβtransition microstructure.
作者
丁小明
高星
张宁
蒋波
DING Xiaoming;GAO Xing;ZHANG Ning;JIANG Bo(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;National Innovation(Qingdao)High Speed Train Material Research Institute Co.,Ltd.,Qingdao 266109,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《热加工工艺》
北大核心
2023年第14期126-130,共5页
Hot Working Technology
作者简介
丁小明(1987-),男,四川绵阳人,高级工程师,博士研究生,主要从事金属材料热加工工艺及性能研究,E-mail:ding_1121@163.com;通讯作者:蒋波,男,副教授,博士,主要从事先进金属材料的组织及性能研究,E-mail:jiangbo@ustb.edu.cn。
