固溶温度对TA4-0.5B钛合金组织及性能的影响  

Effect of solution temperature on microstructure and properties of TA4-0.5B titanium alloy

作　　者：刘开元 黄智荣 于佳新 侯美玉 许耀平 余堃 肖寒[1] Kai-yuan;HUANG Zhi-rong;YU Jia-xin;HOU Mei-yu;XU Yao-ping;YU Kun;XIAO Han(Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Titanium Industry Co.,Ltd.,Chuxiong 651200,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]云南钛业股份有限公司,云南楚雄651200

出　　处：《塑性工程学报》2024年第12期170-177,共8页Journal of Plasticity Engineering

基　　金：云南省重大科技专项计划项目(202202AB080016)。

摘　　要：针对真空非自耗电子束熔炼的TA4-0.5B铸锭,对其热轧后进行固溶时效处理,确定其最佳固溶温度。采用光学显微镜、X射线衍射仪、扫描电镜和万能材料试验机,研究不同固溶温度板材的微观组织演变和力学性能。结果表明:在相变点以下,随着固溶温度升高,板材组织由片状组织转变为等轴组织,且晶界有连续明显的α相析出;晶粒发生粗化,平均晶粒尺寸由11.4μm增大到42.4μm。当固溶温度超过相变点时,其组织转变为双态组织,主要由等轴α相、一些条状α相以及TiB相构成;平均晶粒尺寸增大到54.2μm。拉伸结果表明,在相变点以下,随着固溶温度升高,板材强度、塑性逐渐降低,断裂方式由韧性断裂转变为脆性断裂。相较热轧板材性能,固溶温度720℃时板材的综合性能最优,抗拉强度为828.2 MPa,提高了10.99%。当固溶温度超过相变点时,经固溶时效处理后的板材综合性能最差。For TA4-0.5B ingot melted by vacuum non-consumable electron beam,solution aging treatment was carried out after hot roll-ing,and the optimal solution temperature was determined.Using optical microscope,X-ray diffractometer,scanning electron microscope and universal material testing machine,the microstructure evolution and mechanical properties of sheets at different solution temperatures were studied.The results show that below the phase transition point,with the increase of solution temperature,the microstructure of the sheet changes from lamellar structure to equiaxed structure,and there are continuous and obviousαphase precipitation at the grain bound-ary.The average grain size increases from 11.4μm to 42.4μm.When the solution temperature exceeds the phase transition point,the microstructure is transformed into bimodal structure,which is mainly composed of equiaxedαphase,some stripαphase and TiB phase.The average grain size increases to 54.2μm.The tensile results show that the strength and plasticity of the sheet decrease gradually with the increase of solution temperature below the phase transition point,and the fracture mode changes from ductile fracture to brittle frac-ture.Compared with the properties of hot rolled sheet,the comprehensive properties of the sheet with solution temperature of 720℃are the best,and the tensile strength is 828.2 MPa which is increased by 10.99%.When the solution temperature exceeds the phase transi-tion point,the comprehensive performance of the sheet after solution aging treatment is the worst.

关 键 词：钛合金 固溶时效 组织演变 抗拉强度 伸长率 

分 类 号：TG166.5[金属学及工艺—热处理]