Abstract:The effects of heat treatment and solidification cooling rate on the microstructure and mechanical properties of as-cast Ti-15-3 alloy prepared by induction skull melting method were investigated. Results show that the microstructure of as-cast Ti-15-3 alloy changes from the features of simplified and larger size of beta grains to finer grain size with increasing solidification cooling rate. After solution treatment and different ageing treatment, alpha phase precipitates in grains interior as well as in grain boundaries. Due to the modification of the precipitate phase, the tensile strength and elongation of the alloy are imp roved simultaneously. A good combination of the values of 1.406GPa of σ_b and 4.5% of δ was obtained, which will be satisfied the use of this kind of alloy in critical areas.

Key words: cast Ti-15-3 alloy; solidification cooling rate; heat treatment; microstructure; mechanical properties