热处理对钛涂层结构和性能的影响

Effect of heat treatment on microstructure and properties of Ti coating

采用低温高速火焰喷涂在A3钢表面制备了纯钛涂层,涂层经850℃×4 h真空热处理后对其组织和性能进行了分析。结果表明：涂层内部粒子之间以及涂层与基体之间均发生了扩散,局部形成了冶金结合。XRD分析表明,热处理没有改变涂层的相结构组成;热处理后涂层的显微硬度值是热处理前的2倍,而结合强度超过了50 MPa,对涂层热处理前后的电化学测试表明,热处理后涂层由于致密性提高,其自腐蚀电流密度降低了,涂层的耐腐蚀性能提高了。

Pure Ti coating was deposited on A3 steel by low temperature high velocity oxygen fuel spraying,and the microstructure and properties of the coating were analyzed after 850 ℃ × 4 h vacuum treatment. The results show that diffusion occurred between the particles in the coating and between the coating and the substrate,and metallurgical bonding was formed locally. It is found by XRD analysis that the heat treatment did not change the phase structure of coating. The microhardness of the coating was enhanced two times after the heat treatment,while the bonding strength is more than 50 MPa. Electrochemical tests show that due to the increase of the compactness,the selfcorrosion current density decreased and the corrosion resistance of the coating was improved after the heat treatment.