Microstructures and Properties of TC17 Powder Metallurgy Titanium Alloy Prepared by Laser Sintering/Isothermal Forging

The laser sintering + isothermal forging technology was used to prepare excellent powder metallurgy TC17 titanium alloy, and the influence of technology on the microstructure and properties was investigated. The results indicated that the microstructure of laser sintered TC17 titanium alloy was comprised of coarse columnar beta grains. After isothermal forging up and below beta transus, followed by heat treatment, laser sintered Widmanstatten structure was broken effectively, and transformed into plate, fine and equiaxed alpha phase. Only adopting isothermal forging below, beta transus and heat treatment, the microstructure consisted mainly of fine and equiaxed alpha phase, but little amount of primary beta grain boundary was still remained owing to uniform deformation. After isothermal forging and heat treatment, the plasticity of the alloy at room temperature was increased obviously with little change of the strength, resulting in excellent match between strength and plasticity.