反应爆炸喷涂制备Ti-B-C-N陶瓷涂层的显微结构分析

Microstructure analysis of reactive detonation sprayed Ti-B-C-N ceramic coating

对Ti-B4C-Co粉末进行了喷雾造粒法处理,获得了粉末直径为10~50μm的球形度良好的喷涂粉末,并在750℃真空热处理1 h,粉末中含氧量大大降低。以热处理后的造粒粉为喷涂材料,采用反应爆炸喷涂法获得了厚度为50~70μm的Ti-B-C-N复合涂层,对不同工艺参数下的涂层物相、显微结构以及人工海水中的电化学行为进行了分析。结果表明,在不同参数下获得的涂层物相有所差异,涂层中均含氧化物。在氧乙炔比为1∶0.85的工艺条件下获得的涂层较致密,涂层较厚。不同工艺参数下获得的涂层在电解液中性能稳定,自腐蚀电位均高于碳钢基体,存在明显的钝化区,涂层的耐蚀性得到了显著提高,氧乙炔比为1∶0.85的工艺条件下获得的涂层耐蚀性更佳。

Ti-B4C-Co powders were treated by spraying-drying method,and the excellent spherical powders with diameter of 10-50 μm were obtained. The oxygen content of powders greatly decreases after vacuum heat treatment at 750 ℃ for 1 h. Ti-B-C-N composite coating with thickness of 50-70 μm was prepared by reactive detonation spraying. The phases,microstructure and electrochemical behavior of the coating in artificial seawater solution were investigated. The results show that the phases of coating are different prepared at different parameters,and the oxide exists in the coating. The coating prepared at O2/ C2H2of 1∶ 0. 85 is denser and thicker and has the best anticorrosion property. The property of Ti-B-C-N composite coating is stable in artificial seawater solution. The corrosion potentials of coatings are more positive than that of the carbon substrate. The passivation zone obviously occurs during polarization,which indicates the anticorrosion property of coating is remarkably promoted.