Microstructure and formation mechanisms of TiNiNb amorphous powder prepared by mechanical alloying

Three high-purity (pure ≥99%) metal powders of Ti, Ni, and Nb (the atomic ratio of Ti, Ni, and Nb is Ti:Ni:Nb = 47%:44%:9%) were subjected to high-energy ball milling to explore the mechanical alloying process of TiNiNb alloy. Then, the phase transformation, microstructure and crystallization characteristics of the alloy powders were investigated and analyzed. The results show that the amorphous phase began to appear when the time reached 30 h. With the increase of milling time, the amorphous content gradually increased and tended to be stable, when the milling time reached 50 h. As for particle size, in the initial stage of ball milling, the powder particles were not obvious refined. Nevertheless, when the powder was milled for 30 h, the powder particles were significantly refined, the particle agglomeration was weakened, and the particle size became more uniform. When the ball milling reached 70 h, the average size of powder particles gradually reached stabilization.