Phase transformations during continuous heating: effect of Sn addition on the microstructure of Ti-13Mo alloy

Abstract

The addition of Sn to the Ti-Mo system can diminish the formation of ω phase and slow down the precipitation kinetics of α phase due to the low atomic diffusivity of Sn atoms in Ti. To explore α phase precipitation in Ti-13Mo and Ti-13Mo-6Sn (wt.%) alloys, differential scanning calorimetry (DSC) was applied using different heating rates to determine ω phase dissolution, α phase precipitation and β transus temperatures. The DSC results were then used to determine the aging heat treatment temperatures. Samples were heat-treated at 600 °C for 1 h and 24 h to examine microstructure features. The addition of Sn to Ti-13Mo alloy was found to increase the β phase lattice parameter, increasing β transus temperatures and resulting in microstructures with heterogeneous and coarser α phase precipitation.