Influence of annealing on the microstructure and hardness of Ti67.79Fe28.36Sn3.85 nanocomposite rods

The microstructure of a rod with composition Ti67.79Fe28.36Sn3.85 prepared by suction casting consists of nanometer-sized eutectic lamellae of FeTi and β-Ti and a few β-Ti dendrites. A coarsening of the microstructure is observed from the edge towards the center of the rod. The hardness along the rod radius was evaluated by nanoindentation. The annealing effects on the microstructure of the alloy were investigated. Large hardness values are preserved even after annealing to 650 °C for several hours.