Surface modification of plasma spraying A_l2O₃–13 wt% TiO₂ coating by laser remelting technique

Abstract An Al 2 O 3 –13 wt% TiO composite ceramic coating was prepared on the TiAl alloy surface by plasma spraying and laser remelting combined technique. The morphology, microstructure, phase composition of were analyzed scanning electron microscopy, energy disperse spectroscopy, x-ray diffraction. bonding strength, microhardness, wear resistance, erosion thermal shock resistance also tested. Results demonstrated that after processing remelting, particles refined, lamellar structure disappeared, density increased. A layer basically without crack other defects gained. Due to metastable-phase γ -Al converted into stable-phase α . Influenced low conductivity materials, whole is impossible realize during remelting. remelted formed isometric crystal zone with small grain size, sintering zone, residual zone. strength microhardness improved significantly superior those original layer. Laser specimens still represented typical brittle characteristics. Cracks initiated expanded near surface, finally leading breakage layer, mainly manifested peeling. With respect failure mode, corner peeling major mode spraying. Differently, considerable local peelings found at center influences performances are as decreased initial decelerated expansion, changes in modes coating.