Open AccessInfluences of Laser Remelting on Hot Corrosion Resistance of Plasma-sprayed Nanostructured Al2O3-13wt.%TiO2 Coating
Author(s) -
Dongsheng Wang,
Rui Xiao,
Guang Qu,
Xinhua Zhou
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1965/1/012084
Subject(s) - materials science , corrosion , coating , microstructure , metallurgy , diffractometer , ceramic , layer (electronics) , lamellar structure , phase (matter) , plasma , alloy , laser , composite material , scanning electron microscope , chemistry , physics , organic chemistry , quantum mechanics , optics
Nanostructured Al 2 O 3 -13wt.%TiO 2 ceramic coatings were prepared on the TiAl alloy surface by using the plasma spraying and plasma spraying-laser remelting composite technology, respectively. Hot corrosion behaviors of these two coatings in 75%Na 2 SO 4 +25%NaCl (mass fraction) fused salts under 850 °C were discussed. Moreover, phases and microstructures of specimens after the corrosion were analyzed by X-ray diffractometer (XRD) and scanning electro microscope (SEM). Effects of laser remelting on hot corrosion resistance of coatings were explored. Results demonstrated that hot corrosion of ceramic coating prepared by plasma spraying is serious, but the hot corrosion resistance can be improved effectively after laser remelting. Laser remelting specimens show the higher hot corrosion resistance for two reasons. On the one hand, laser remelting forms a uniform and dense remelting layer by eliminating the lamellar structures and most pores of the coating layer, thus decreasing the corrosion diffusion channels during hot corrosion. On the other hand, laser remelting changes the metastable-phase γ-Al 2 O 3 into stable-phaseα-Al 2 O 3 .