陶瓷壳型面层材料与Ti46Al1B阀门铸件的界面反应

分别采用Al2O3与Y2O3为壳型面层材料,离心铸造了Ti46Al1B(原子分数,%)合金阀门铸件,通过SEM,XRD以及气体分析等方法,确定壳型内表面物相组成、铸件与壳型反应层厚度以及合金的进氧情况,分析了壳型材料与Ti46Al1B合金的反应机理.结果表明,Y203和A120s壳型与合金的反应层厚度分别约为90和170 pm,使用Y203壳型时铸件进氧少,其热力学稳定性好于Al2O3壳型,与热力学计算结果相符.Y2O3壳型比Al2O3壳型更适合铸造Ti46Al1B阀门.

INTERFACE REACTION BETWEEN CERAMIC MOULDS AND Ti46Al1B AS-CAST VALVES

Al₂O₃ and Y₂O₃ were used as surface materials of shell mould to centrifugal--cast Ti46Al1B (atomic fraction, %) valves, the interface reaction between shell and alloy and its mechanism were analyzed by SEM and XRD, and oxygen increment in the castings was measured by gas analysis. The results show that the reaction layer thicknesses of Y₂O₃ and Al₂O₃ shells are about 90 and 170 μm, respectively, indicating Y₂O₃ shell has better thermodynamic stability and smaller increment of oxygen in casting than Al₂O₃ shell, which is accordant with thermodynamic calculation. So the Y₂O₃ mould is fitter for casting Ti46Al1B valves than Al₂O₃ mould.