Influence of solution treatment on the microstructure and mechanical property of Ti60 alloy

Abstract:

Both of the α′ and α+α′ martensite microstructures of Ti60 alloy as high temperature titanium alloy used up to 600°C can be obtained by solution treatments at different temperatures. The morphologies of the two microsturctures are compared as well as the tensile properties at room temperature, 300°C and 600°C. The results indicate that all the β phase transforms to α′ phase during quenching, and only about 10% primary α phase retains in the α+α′ microstructure. The little decrease of strength and great increase of ductility can be attributed to the partial solution of primary α phase. The size of dimple observed on the fracture of specimens with α+α′ microstructure at room temperature is larger than that with α′ microstructure. Because the retained primary α phase dedicates to the refinement of β grains, leading to the disturbance of expansion of cracks by increasing the length of grain boundaries. The influence of the primary α phase on the tensile properties decreases with the increasing of the tensile temperature.