Microstructures and Mechanical Properties of NiAl-(Cr) and TiAl-(Cr) Intermetallic Alloys

(Received 4 February 1997, revised 5 August 1997, accepted 8 September 1997)

Abstract
The oxidation resistant light weight aluminides: NiAl and TiAl with ordered B2 and L1 ₀ super lattices show promising mechanical properties for high temperature applications. The ductility and strength properties at room and higher temperatures are strongly dependent upon the degree of ordering of the intermetallic compounds and of the microstructural parameters of the multiphase alloys, such as NiAl-(Cr) and TiAl-(Cr,Si). The presented paper describes and discusses the influence of second phases on the mechanical properties of these intermetallics with special emphasis of structural defects - antistructure atoms - and the dislocation mobility.