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.
作者
周薇
汪畅
刘继雄
李斯韫
刘会群
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)
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。
