Short communication Refinement and characterisation of a thermodynamically stable b-[Ni(Al,Ti)]–b=-[Ni

The Ni–Al–Ti system contains three intermetallic phases, c=, b, and b= which have complementary properties. The objective of the present investigation was to coextrude these three phases to form a metal–metal composite (MeMeC) and investigate the mechanical properties and failure mechanisms of such a material. High strengths, comparable with that of the strongest constituent phase, have been recorded for the MeMeC material. Strength is maintained at a constant level up to 500?C above which it falls progressively. The compressive strain to failure is considerably greater that that expected for monolithic b or b = phases. It has been shown that the interfaces between nominally single phase regions provide lines of weakness along which cracks propagate during compressive loading. Preliminary attempts to strengthen the interfaces by a 24 h heat treatment at 900?C have been carried out. MST/4442