Phase Transformations upon Ageing in Ti15Mo Alloy Subjected to Two Different Deformation Methods

Ti15Mo alloy was subjected to two techniques of intensive plastic deformation, namely high pressure torsion and rotary swaging at room temperature. The imposed strain resulted in the formation an ultrafine-grained structure both deformed conditions. Detailed inspection microstructure revealed presence grains with a size around 100 nm after also contained elongated length up 1 µm. Isothermal ageing 400 °C 500 16 h applied conditions investigate kinetics precipitation α phase recovery lattice defects. Positron annihilation spectroscopy indicated that defects β matrix had already occurred and, terms positron trapping, partly compensated by incoherent particles. At fully offset α/β interfaces. Contrary common coarse-grained material, which precipitates form lamellae, small equiaxed particles condition. A refined two-phase grain sizes below μm is achievable simple followed ageing.