MELT-INFILTRATION AND WETTING TRANSITIONS OF Ni3Al ALLOY INFILTRATED INTO TiC-Al2O3 PREFORMS

TiC-Al2O3-Ni3Al composites have been prepared using a conventional melt-infiltration process. The addition of Al2O3, which is poorly wet by molten Ni3Al, was shown to result in a transition between wetting and infiltration, and wetting/spreading without infiltration, depending upon the Al2O3 particle size and volume fraction. Successful melt-infiltration can be achieved with more coarse Al2O3 particles, resulting in densities comparable to cermets prepared without Al2O3, offering the potential for lowering raw materials costs for these composites.