( 1. 北京航空航天大学 材料科学与工程学院, 北京 100083; 2. 北京航空材料研究院, 北京 100095;
3. 北京科技大学 新金属国家重点实验室, 北京 100083)
摘 要: 采用热等静压技术处理了高铌TiAl合金铸锭， 对直径为115mm的高铌TiAl合金铸锭在1150~1300℃进行了热锻开坯。 结果表明：热等静压处理后的高铌TiAl合金由大量粗大的α2γ片层晶粒和少量的γ等轴晶、 B2相等组成，晶粒度约为80~150μm； 通过变形量为75%的2次锻造成形后锻饼表面和内部质量较为完好， 没有出现裂纹和太多的氧化现象；铸态粗大片层组织在变形后基本破碎， 晶粒得到明显细化。
关键字: 高铌TiAl合金；热锻开坯； 微观组织
TiAl alloy containing high Nb
（ 1. Research Institute of Advanced Materials,
Beijing University of Aeronautics & Astronautics, Beijing 100083, China;
2. Beijing Institute of Aeronautical Materials, Beijing 100095, China;
3. State Key Laboratory for Advanced Metals and Materials,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract: The ingot of as-cast TiAl alloy containing high Nb was dealed with HIP(hot isostatic pressing). The hot forging for large ingot with 115mm in diameter of the TiAl based alloy containing high Nb was carried out in the temperature range of 1150℃-1300℃. The results show that TiAl alloy containing high Nb is composed of small amount of γ and B2 phase and large of coarse α2γ lamellar structure with colony size of about 80-150μm after HIP. After twice forging with total deformation degree of 75%, the quality of the surface and inside of the pancake is good, and there is no cracks and evident oxidation. The as-cast lamellar structure is basically broken down and the grain gets fined obviously.
Key words: TiAl alloy containing high Nb; hot forging; microstructure
