TiAl合金薄壁环形件精铸成形工艺研究

Investment Casting Process of TiAl Alloy Thin-walled Circular Component

针对TiAl合金室温塑性低、制备过程容易开裂等问题,采用氧化物陶瓷型壳、真空自耗凝壳熔炼和离心浇注相结合的方式,研究了Ti-48Al-2Cr-2Nb合金的精密铸造成形技术。通过浇注系统设计和浇注工艺优化,采用离心浇注成功制备出TiAl合金环形铸件,直径达260mm,80%区域壁厚在1.5~3.0mm,经无损检测发现铸件无裂纹、缩孔缺陷。

Aiming at the problem of TiAl alloy＇s low room temperature plasticity and cracking tendency,investment casting process of Ti-48 Al-2 Cr-2 Nb alloy was investigated by the combination methods of oxide ceramic shell,VAR an centrifugal casting.TiAl alloy thin-walled circular component has been manufactured successfully with a diameter of 260 mm and wall thickness of 1.5-3.0 mm in the 80%area after the optimization of gating system and pouring process.Through the nondestructive testing of metallurgical quality,absence of crack and shrinkage cavity defects can be observed.