Research on Protective Coatings of Nb Ti Al Based Alloys and Analysis of Their Oxidation Resistance Mechanism
Nb Ti Al based alloys were synthesized using vacuum electron beam melting and arc furnace technology.Si-Cr-W protective coatings were prepared on the alloy surface using slurry melting technology,and the oxidation resistance of the coatings was evaluated at 1 250 ℃.The microstructure and element distribution of the coatings before and after oxidation were analyzed using scanning electron microscopy and energy scattering spectroscopy.The research results indicate that the main components of protective coatings include metal silicides such as Nb,Ti,Cr,W,etc.Its oxidation resistance mechanism at high temperatures is through the oxidation decomposition of metal silicides,generating SiO2 and composite metal oxide layers,effectively blocking the penetration of oxygen.After undergoing 100 hours of oxidation testing,the external structure of the coating showed a loose state due to oxidation,but the internal structure still maintained a dense characteristic,verifying that the coating has excellent oxidation resistance under high temperature conditions.
slurry melting and firingprotective coatingmetal silicideshigh temperature antioxidant performance
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