摘要
α+β两相区轧制的TC4钛合金丝材经不同工艺热处理后,获得等轴组织、双态组织和片层组织,研究了微观组织特征及其对合金拉伸性能和疲劳性能的影响。结果表明:等轴组织α晶粒最为细小且具有较高的位错密度,表现出最高强度;双态组织α相较等轴组织显著长大,位错密度明显降低,具有最好的工艺塑性;片层组织原始β晶粒粗大,塑性最低。3种组织中片层组织疲劳性能最好,当裂纹长度<250μm时,不同显微组织对应的裂纹扩展速率差异较大,片层组织的扩展速率最低,等轴组织最高;当裂纹长度>250μm时,3种组织的裂纹扩展速率无显著差异。综合考虑TC4钛合金丝材的力学性能和工艺塑性,应选择双态组织作为产品的最终组织状态。
By different heat treatments and microstructural analysis methods,microstructure characteristics of equiaxed structure,duplex structure and lamellar structure for TC4 titanium alloy were observed in this study.Meanwhile,the influence of different microstructure on tensile property and fatigue property was studied.The results show that equiaxed structure with the finestαgrain and high dislocation density exhibits the highest strength;duplex structure,with biggerαphase and lower dislocation density than that of equiaxed structure,presents excellent process plasticity;lamellar structure,with coarse originalβgrain,presents the lowest plasticity.While,the lamellar structure presents the best fatigue property.When crack size is lower than 250μm,the crack growth rates of three microstructures are obviously difference.The lamellar structure exhibits the lowest crack growth rate,and it is the highest for equiaxed structure.When crack size is higher than 250μm,there is no obvious difference.Considering the mechanical properties and process plasticity of TC4 titanium alloy wire,duplex structure should be selected as the final structure state of the products.
作者
王清瑞
沙爱学
黄利军
黄旭
Wang Qingrui;Sha Aixue;Huang Lijun;Huang Xu(Beijing Institute of Aeronautical Materials AECC,Beijing 100095,China)
出处
《钛工业进展》
CAS
2022年第4期12-15,共4页
Titanium Industry Progress
基金
国家科技重大专项(J2019-Ⅷ-0003-0165)
关键词
TC4钛合金丝材
微观组织
拉伸性能
疲劳性能
TC4 titanium alloy wire
microstructure
tensile property
fatigue property
