Y元素对铸造Ti-6Al-4V合金微观组织与力学性能的影响  

Effect of Y Addition on the Microstructure and Mechanical Properties of the As-cast Ti-6Al-4V Alloy

作　　者：王利卿 肖邦 赵少阳[1] 谈萍[1] 李增峰[1] 殷京瓯[1] 沈垒 王建忠[1] 汤慧萍[1] Wang Liqing;Xiao Bang;Zhao Shaoyang;Tan Ping;Li Zengfeng;Yin Jing’ou;Shen Lei;Wang Jianzhong;Tang Huiping(State Key Laboratory of Porous Metal Materials,Northwest Institute for Non-ferrous Metal Research,Xi'an 710016,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北有色金属研究院金属多孔材料国家重点实验室,陕西西安710016 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2020年第12期4142-4145,共4页Rare Metal Materials and Engineering

基　　金：National Key Research and Development Program of China(2017YFB0305800)。

摘　　要：研究了Y元素合金化对铸造Ti-6Al-4V合金微观组织与力学性能的影响。铸态合金微观组织与力学性能分别利用金相显微镜、扫描电镜、透射电镜和拉伸试验进行表征。结果显示,Ti-6Al-4V合金呈现典型的魏氏组织特征。添加Y元素后,合金中形成Y2O3颗粒并分布在初生β晶粒的晶界处,同时在晶界两侧形成平行的α/β层片结构,而晶粒内部形成相互交叉的α/β层片结构,即Y2O3明显改变了Ti基体片层组织形貌。相比于Ti-6Al-4V合金,添加Y元素之后,合金的屈服强度和抗拉强度稍有提高,但是平行的α/β层片结构和Y2O3颗粒引起合金由解理断裂向沿晶断裂转变,进而导致延伸率显著减小。所以,Ti基体微观组织变化对合金力学性能同样具有重要作用。The effects of yttrium(Y)addition on microstructures and properties of the as-cast Ti-6Al-4V alloys were studied.The microstructure and mechanical properties were characterized by optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and tensile testing.The results show that Ti-6Al-4V alloy exhibits typical Widmanstatten structure.With Y addition,Y2O3 particles form and primarily distribute along the prior-βgrain boundaries,and it induces the formation of special paralleledα/βlamellas on either side of the prior-βgrain boundaries.While alternateα/βlamellas are observed inside the grains of Ti-6Al-4V-0.3Y alloys.Compared with Ti-6Al-4V,the Y addition improves the strength slightly.Both the paralleledα/βlamellas and Y2O3 cause the transformation from cleavage fracture to intergranular fracture and the significant decrease in elongation.Therefore,the variation of the microstructure of Ti matrix caused by Y2O3 also plays an important role in the ductility of the alloys.

关 键 词：Ti-6Al-4V-0.3Y合金 Y2O3颗粒 α/β层片组织 力学性能 断裂行为 

分 类 号：TG146.23[一般工业技术—材料科学与工程]