Laser/argon-arc strengthening of titanium alloy surface with Deloro matrix composites

Abstract The hard composites were fabricated by an argon-arc clad (AAC) of the Deloro22-Si3N4-B4C mixed powders on the TA1 titanium alloy substrate, which exhibited a relative coarse compact microstructure; then this substrate surface was treated by a laser beam, the microstructure evolution and formation mechanism of such AAC composites under the actions of laser surface strengthening (LSS) technique also the vacuum tempering process will be explored. Research results indicated that twice heat treatments changed greatly growth directions of the crystals, resulting in a net-like microstructure; also large amount of the atoms could obtain sufficient energy to exceed a potential barrier due to the extreme high temperature of the laser produced molten pool (laser-pool), forming the twin crystals; the vacuum tempering was able to remove the accumulation of the residual stress to a certain degree, improving the plastic and toughness performance of such LSS composites. To have a quantitative understanding of the AAC/LSS technologies effects, this paper has provided the laser technological/related theoretical basis to modify the ACC composites on the titanium alloy.