Published online by Cambridge University Press: 15 February 2011
NiAl is well known for its low density, superb oxidation resistance and low ductile to brittle transition temperature. It is equally renowned for its low room temperature fracture strength and poor high temperature creep strength. A compositing approach has been used to introduce chopped and aligned FP Al2O3 into a matrix of fine grain NiAl via a powder metallurgical approach. This resulted in composites with approximately 40 vol. per cent undamaged alumina reinforcement. Fiber orientation effects on strength have also been characterized. Room temperature tests resulted in yield strength increases of 425% for chopped FP reinforcements and 800% for aligned composites. Elevated temperature tests conducted at 1200°C were even more dramatic in their strength increment with 200% and 3600% increases respectively. Fractographic results show matrix ductility, fiber-matrix decohesion and minimal fiber pull-out.