Microstructures and Properties of TC4 Alloy Bar with Different Heat Treatments

Microstructure and properties of TC4 alloy bars under various treatment processes were investigated.Results show that with increasing of single annealing temperature,the microstructure of TC4 alloy bar changes from equiaxed to bi-modal type and the tensile strength decreases while elongation and reduction of area first increase and then decrease,and the impact toughness increases continuously.With the increase of duplex annealing temperature,the microstructure of TC4 alloy bar changes from bi-modal to equiaxed type,of which the mechanical properties of the alloy with bi-modal microstructure are better.For the solution aging bar,the microstructure changes from basket-weave to bi-modal and equiaxed types,and the mechanical properties of the bar decrease with aging temperature increasing.The best comprehensive mechanics performances can be achieved under the heat treatment parameters of solution at 940℃ and aging at 530℃.