Observation of the microstructure of the metastable Ti15Mo alloy after ageing

Abstract

Omega phase particles can be observed by conventional SEM. Metastable Ti15Mo alloy was annealed at 500 °C for 16 hours. During annealing, ω phase particles grew and got chemically stabilized by expelling Mo atoms. As the result, these ellipsoidal particles, approx. 100 nm long and 50 nm wide can be observed using back-scattered electrons signal in conventional SEM due to chemical contrast. TEM study proved that these particles indeed belong to ω phase. Co-existence of β, ω and α phases was observed. Thin α lamellae were observed along with distorted ω phase particles by TEM.