Effect of open porosity of Y2O3 ceramic on the apparent contact angles and interactions between Ti47Al alloys and Y2O3 ceramic

Abstract

The effect of open porosity of Y2O3 ceramic on the apparent contact angle and interaction between molten Ti47Al alloy and Y2O3 ceramic substrates under pure Ar was investigated by using a sessile drop method at 1600°C. As the open porosity increased from 9.6% to 30.3%, the spreading rate of molten Ti47Al alloys on Y2O3 ceramic substrates reduced from 2.3 to 1.1°/s; meanwhile, the final equilibrium contact angles increased from 55.8° to 63.6°. The microstructure observations revealed that with increasing the open porosity of the Y2O3 substrates, the thickness of sand adhesion at the interfaces of the alloy droplets increased from 5.4 to 15.7 μm, and ceramic particles in the alloy matrix increased as well. The increasing contact area between the molten alloy and the substrate played a dominant role in determining the interaction on TiAl/Y2O3 interface.