intermetallic phase formation during combustion synthesis of mechanically activated ni-ti alloy

intermetallic phase formation and oxidation reaction during combustion synthesis (cs) of ni-ti equiatomic mixture are affected by mechanical activation (ma) and pre-heating conditions. important parameters are ignition time, reaction duration, temperature rise, microstructural change, titanium oxidation and intermetallic phase formation. superelasticity and shape memory effects are influenced by two-stage austenite-rhombohedral and rhombohedral-martensite transformations detected by differential scanning calorimetry (dsc) and scanning electron microscopy (sem) of the combusted samples. tension tests indicated superelastic behavior after 1 h, production of ni3ti after ½ h and delayed superelastic/thermoelastic behavior after 2 h ma. results indicate that pre-combustion heating fosters mono-phase formation and titanium oxidation; while mechanical activation lowers ignition-start-time, synthesis-duration and ni3ti formation.