合金组织和性能的影响
(1. 哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001
2. 广州有色金属研究院 粉末冶金研究所，广州 510651)
摘 要: 采用水冷铜坩埚真空感应熔炼技术制备名义成分为Ti-45Al-5.4V-3.6Nb-0.3Y(摩尔分数，%)的高质量合金铸锭，采用XRD、OM、SEM及TEM等分析手段分析研究该合金的组织演变过程，同时进行力学性能测试。结果表明：Ti-45Al-5.4V-3.6Nb-0.3Y合金具有近层片组织结构，由γ、α2和β三相组成；经包套锻造处理后，合金的晶粒尺寸显著减小，由100 μm下降至7 μm左右；合金的室温屈服强度提高220 MPa左右，达到620 MPa，室温伸长率提高到1.08%；经700 ℃处理后，该合金的屈服强度从562 MPa升高到708 MPa，伸长率从7.6%提高到35.55%。
关键字: TiAl合金；包套锻造；组织；性能
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Department of Powder Metallurgy, Guangzhou Research Institute of Non-ferrous Metals,
Guangzhou 510651, China）
Abstract:A high quality TiAl alloy ingot with nominal composition of Ti-45Al-5.4V-3.6Nb-0.3Y (mole fraction, %) with nearly lamellar structure was prepared by introduction skull melting (ISM) in a water-cooled copper crucible. The microstructure evolution were detected by X-ray diffractometry (XRD), optical microscopy (OM), scan electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, the mechanical properties were also tested. The result show that the Ti-45Al-5.4V-3.6Nb-0.3Y alloy prepared is composed of γ, α and β phases, the grain size of as-forged alloy decreases from 100 μm to 7 μm, the room temperature yield strength increases by about 220 MPa and reaches 620 MPa, and the ductility increases to 1.08% after canned forging. After treated at 700 ℃, the yield strength and ductility of this alloy exhibit the similar increasing trend as that at room temperature after forging, with yield strength of 708 MPa and elongation of 35.55%.
Key words: TiAl alloy; canned forging; microstructure; properties
