Differences in crystallisation behaviours during cooling and post-heating processes of Ti based metallic powders

Abstract

The different crystallisation behaviours of Ti based metallic powders were systematically investigated. Governed by a higher transition temperature (a lower supercooling degree), the composition of the microsized precipitations (Sn and Ti rich) of cooling significantly varies from that of the glassy matrix (Cu and Zr rich). On the other hand, a kinetics limited condition (a lower transition temperature) results in nanocrystals and various compositional regions between small atoms (Ti, Ni and Cu) and large atoms (Sn and Zr) for the post-heating. The different crystallisation mechanisms are considered to be determined by the synergetic effect of thermodynamics (supercooling degree) and kinetics (transition temperature).