Processing and Characterization of Mechanically Alloyed NiAl-Based Alloys

Abstract : Mechanical alloying of powders followed by hot extrusion has been used to produce NiAl-based materials. The technique is capable of producing fully dense, free of cracks, fine grained materials containing a bimodal distribution of aluminum oxide dispersoids. The mechanically alloyed materials produced in our laboratory are much stronger at both ambient and elevated temperatures and significantly more ductile than their cast counterparts. Minimum creep rates in the MA NiAl are on average three orders of magnitude lower than that in their cast counterparts. The creep resistance of the MA NiAl is better than that of solid solution- and other dispersion-strengthened NiAl and comparable to the creep resistance of precipitation-strengthened NiAl. Improved mechanical properties of the present materials result from their unique microstructure. Mechanical alloying, NiAl-Aluminides, Intermetallics strength, Ductility and creep in NiAl.