Nb-Ti-Al基合金的防护涂层研究及其抗氧化性能机理分析

Research on Protective Coatings of Nb Ti Al Based Alloys and Analysis of Their Oxidation Resistance Mechanism

利用真空电子束熔炼与电弧炉技术合成了Nb-Ti-Al基合金,利用料浆熔烧技术在合金表面制备了Si-Cr-W防护涂层,并对1250℃条件下的涂层抗氧化性能进行了评估,同时采用扫描电子显微镜和能量散射光谱研究分析了氧化前后的涂层微观形态和元素分布。研究结果表明:防护涂层的主要成分包括Nb、Ti、Cr、W等金属硅化物,其在高温下抗氧化机制为通过金属硅化物的氧化分解,生成SiO2和复合金属氧化物层,从而有效阻挡氧气的渗透。在经历了100 h的氧化测试后,涂层的外部结构因氧化而呈现出疏松的状态,但内部结构仍然保持着致密的特性,验证了该涂层在高温条件下具有出色的抗氧化性能。

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 1250℃.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.