Microstructure and Properties of Boron Containing High Temperature Titanium Alloy in Thermal Deformation and Solution Aging States

The microstructure and tensile properties of boron containing high temperature titanium alloy in hot deformed state and different solution+aged states were studied. The fracture characteristics of boron containing high temperature titanium alloy in room temperature and high temperature tensile processes were analyzed and the strengthening mechanism of the alloy was investigated. The results show that there is no significant difference in the distribution, location and size of whisker in boron containing high temperature titanium alloys under different states. The microstructure of the matrix is fine equiaxed grain, and the primary α phase is dissolved after solution treatment in the two-phase zone, and it is transformed into a dual-state structure. The cooling rate after solution mainly affects the precipitation of secondary α phase from β transformed tissues during the subsequent aging process. The strength of boron containing high temperature titanium alloy in hot deformation and heat treatment state has remarkable advantages. The tensile strength of 1547 MPa at room temperature and 745 MPa at 650 ℃ can be obtained by the heat treatment process of two phase solution quenching and aging. The excellent strength of boron containing high temperature titanium alloy is mainly due to the bearing strengthening of whisker and matrix microstructure refinement, and the extremely fine disordered β transition structure formed during aging after solution quenching treatment is the main reason that the boron-containing high-temperature titanium alloy has ultra-high strength.