Effect of annealing temperature and soaking time on microstructures and microhardness of laser deposition manufacturing TA15 titanium alloy

TA15 titanium alloy bulk specimens were prepared with spherical powder and forging substrates in laser deposition manufacturing. The effects of annealing temperature and soaking time on microstructure characteristics and microhardness were investigated by optical microscope (OM), scanning electron microscopy (SEM) and microhardness instrument. The experimental results show that alpha phase grows fully resulting from annealing temperature increase and longer soaking time at same annealing temperature. The width of the alpha phase becomes larger with the extension of the soaking time. The percentage content of alpha phase grows with annealing time extension. Alpha phase exists different growth direction in different annealing soaking time. There are some certain relationship between microhardness and volume content of alpha phase, microhardness is enhanced with the increases of percentage content of alpha phase.