Hot corrosion resistance of plasma-sprayed MCrAlY coatings by laser remelting on TiAl alloy surface

The MCrAlY coatings were prepared by plasma spraying on TiAl alloy surface, laser remelting experiment had been carried out and the hot corrosion resistance of TiAl alloy, plasma-sprayed and laser-remelted MCrAlY coatings in 5%Na₂SO₄+25% NaCl(mass fraction) molten salt at 850℃ were researched. The hot corrosion failure mechanisms of three kinds of materials were analyzed and the influence of laser remelting on hot corrosion behavior of plasma-sprayed MCrAlY coating were discussed. The results show that the plasma-spayed MCrAlY coating has better oxidation resistance than the original TiAl alloy, and the laser-remelted coating has the best oxidation resistance. The hot corrosion of MCrAlY coating included surface oxidation and internal sulfide, and produced Al₂O₃, Cr₂O₃, NiO, NiCr₂O₄, Ni₃S₂ and CrS et al.