TC21合金时效过程中的相变研究  

Study on Phase Transformation of TC21 Alloy During Aging Treatment

作　　者：王义红[1] 寇宏超[1] 朱知寿[2] 李金山[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]北京航空材料研究院,北京100095

出　　处：《热加工工艺》2010年第4期132-135,共4页Hot Working Technology

摘　　要：采用XRD、SEM、TEM及显微硬度测试等手段,系统研究了TC21合金固溶处理后的相变以及合金在550～850℃时α"相在时效过程中的分解机制及组织演变规律,结果表明:1000℃固溶30min淬火后,TC21合金形成α"马氏体,且合金中存在少量β及O相(Ti2AlNb);随时效温度的升高,α"相逐步发生α"→α+α"富→α+β亚稳→α+β,α''+α'+β亚稳→α+β,α''→α+β等分解过程;TC21合金的显微硬度依赖于时效温度和时效时间,时效时间延长,合金显微硬度先迅速增大,达到最大值后再逐渐减小。时效温度升高时,合金显微硬度达到最大值的时间缩短,且合金最终的显微硬度随时效温度的升高而降低。Phase transformation during solution treatment,the decomposition mechanism and microstructure evolution of α＂ phase during aging treatment were systematically studied using XRD,SEM,TEM and microhardness analysis.The results show that TC21 alloy solution treated at 1000 ℃ for 30 min,water quenched,present an martensitic structure consisting of α＂ phase and little β phase,O phase （Ti2AlNb）.With the increase of aging temperature,the mechanism of the decomposition of α＂ phase is α＂→α＋α＂富→α＋β亚稳→α＋β,α＂＋α＇＋β亚稳→α＋β,α＂→α＋β.The microhardness of TC21 alloy depends on the aging temperature and aging time.The microhardness increases rapidly,reachs the maximum and gradually decreases with increasing aging time,with increasing aging temperature,the time to reach the maximum microhardness and the final microhardness of TC21 alloy decreases.

关 键 词：钛合金 相变 时效 α"相 

分 类 号：TG156.92[金属学及工艺—热处理]