Metastability of Mechanically Alloyed and Spark Plasma Sintered Co₅₀Ti₅₀ Powder

Abstract

High purity cobalt and titanium powders were equiatomically mixed and mechanically alloyed. The microstructure and phase transformation occurred on the powder product during its densification using the spark plasma sintering SPS technique were analyzed. CoTi and CoTi₂ intermetallic compounds formed after fast sintering. Although metastable CoTi₂ undergoes partial CoTi transformation the lattice parameter and micro-Vickers hardness of these sintered compounds show high stability when annealing from 973 to 1273 K. The material thus prepared can be reliably used at these temperatures showing excellent mechanical behavior.