亚稳β型Ti-6Cr-5Mo-5V-4Al合金的时效析出序列及ω和次生α相对拉伸性能的影响  

Ageing precipitation sequence and effect ofωand secondaryαphases on tensile properties of metastableβTi−6Cr−5Mo−5V−4Al alloy

作　　者：周薇 汪畅 刘继雄[2] 李斯韫 刘会群[1,3] Wei ZHOU;Chang WANG;Ji-xiong LIU;Si-yun LI;Hui-qun LIU(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Baoti Group Ltd.,Baoji 721014,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]宝钛集团有限公司,宝鸡721014 [3]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第6期1742-1754,共13页中国有色金属学报（英文版）

基　　金：funded by the National Key Research and Development Program of China(No.2021YFB3700801);by the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China。

摘　　要：研究亚稳β型钛合金Ti-6Cr-5Mo-5V-4Al固溶和时效过程中的析出序列及显微组织和拉伸性能之间的关系。在400~450℃时效时,合金析出等温ω相(ω_(iso)),引起高硬化行为和脆性断裂。在450~500℃时效时,随时效时间增加,ω_(iso)相逐渐演化为次生α相(α_(s))。在更高温度(580~600℃)时效时,ω_(iso)相析出受到抑制,α_(s)相直接从β相析出。由于ω_(iso)相析出,合金在450℃时效12 h时的屈服强度为1368 MPa,伸长率为5.5%。随α_(s)相析出和粗化,合金在600℃时效12 h时的屈服强度为1108 MPa,伸长率提高到15.4%。The ageing precipitation sequence and the relationship between microstructure and tensile properties of metastableβtitanium alloy Ti−6Cr−5Mo−5V−4Al during solution and ageing were investigated.Ageing from 400 to 450°C,isothermalωphase(ω_(iso))precipitated in the alloy,resulting in high hardening and brittle fracture.After ageing at 450−500°C,ω_(iso) phase was gradually replaced by secondaryαphase(α_(s))with the ageing time increasing.At higher ageing temperature(580−600°C),ω_(iso) precipitation was suppressed,andα_(s)phase precipitated directly fromβphase.The yield strength of sample aged at 450°C for 12 h was 1368 MPa and the elongation was 5.5%due toω_(iso) precipitation.The yield strength of sample aged at 600°C for 12 h was 1108 MPa and the elongation was improved to 15.4%due to the precipitation and coarsening ofα_(s)phase.

关 键 词：亚稳态β-Ti合金 时效序列 Ω相 α_(s)相 强度 塑性 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG156.9[金属学及工艺—金属材料]