C元素含量对TiAl合金显微组织与力学性能的影响  

Influence of C Element Content on Microstructure and Mechanical Property of TiAl Alloy

作　　者：宗波[1] 董恒平[1] 冯冲[1] ZONG Bo;DONG Hengping;FENG Chong(Taizhou Institute of Sci.＆Tech.,NUST,Taizhou 225300,China)

机构地区：[1]南京理工大学泰州科技学院

出　　处：《热加工工艺》2018年第16期104-107,共4页Hot Working Technology

基　　金：江苏省高校自然科学研究面上项目(14KJB510014);南京大学固体微结构物理国家重点实验室开放课题项目(M29026);泰州市科技支撑(社会发展)课题项目(TS201506)

摘　　要：通过XRD、SEM观察不同C含量下TiAl合金铸锭的显微组织,并对其进行硬度、抗拉强度测试。研究了C元素含量对TiAl合金显微组织与性能的影响。研究表明：未添加C元素时,TiAl合金晶粒为粗大柱状晶。当C含量为0.3at%时,柱状晶转变为等轴晶。随着C含量的增加,TiAl合金晶粒逐步细化,且层片间距逐渐减小,但并未改变γ相与α2相相间交替层片结构。C含量较少（≤0.3at%）时基体中不会出现第二相;C含量进一步增加,第二相析出明显且不断长大,富集在一起,偏析严重。TiAl合金的力学性能随着C含量增加先增强后减弱,当C含量为0.6at%时,TiAl合金的性能最佳。The microstructure of TiAl alloy ingot with different C contents was observed by XRD and SEM. The hardness and tensile strength of the alloy were tested. The effects of C element content on the microstructure and properties of TiAl alloy were studied. The results show that without adding C elements, TiAl alloy grain is bulky columnar crystal. When the C content is 0.3 at%, the columnar crystal changes into isometric crystal. With the increase of the content of C, TiAl alloy grain is gradually refined, and the layer spacing decreases gradually, which can not change the phase alternating layers structure ofγ phase and α2 phase. When the C content is little（0.3 at% or less）, the matrix can not generate the second phase. When the C content increases furtherly, the second phase precipitates obviously and grows together, and the segregation is severe. The mechanical properties of TiAl alloy increase firstly and then decrease with the increase of C content. When C content is0.6 at%, the performance of TiAl alloy is the best.

关 键 词：TIAL合金 C含量 显微组织 性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]