Powder Metallurgical Processing of Ni–Ti Shape Memory Alloy

Abstract

The near net shape production of homogeneous Ni–Ti intermetallic displaying good shape memory behaviour is attractive, particularly for potential biomaterials applications. This study investigates and characterises equiatomic Ni–Ti shape memory alloy prepared by the compaction and sintering of elemental Ti and Ni powders. Phase development during sintering was determined using X–ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis, and dimensional integrity ,of the compacts was monitored during sintering. The shape memory behaviour of the Ni–Ti compacts was assessed using differential scanning calorimetry. Employment of a combined solid state and liquid phase sinter cycle produced homogeneous Ni–Ti intermetallic containing 35% porosity and displaying shape memory transformation enthalpy similar to that of commercially produced wrought Ni–Ti material. PM/0746