Mechanical properties and thermal stability of rolled W-0.5Â wt% TiC alloys

In this paper, hot rolled W-0.5 wt% TiC alloys are fabricated via a combination of powder metallurgy and subsequent hot rolling with 65% thickness reduction. The as-rolled alloys show high strength of 789 MPa at 200 °C with a total elongation of 4.8%. We have explored the mechanical properties and thermal stability of W-0.5 wt% TiC alloys after annealing at various temperature. The corresponding results show that hardness and fracture strength slightly decrease with increased annealing temperature up to 1500 °C owing to recovery. While after annealing at 1600 °C for 1 h, the fracture strength of W-0.5 wt% TiC alloys decreases significantly due to full recrystallization and grain growth. The thermal conductivity increases with increased annealing temperature. The observed incubation time for recrystallization and the corresponding recrystallization thermal activation energy (~612 kJ/mol) for this rolled plates indicate a sufficient thermal stability at service temperature below 1200 °C. This good thermal stability is attributed to the nanosized TiC dispersion strengthened structures.