铁基非晶增强碳化钨涂层的微观结构与性能

Microstructure and properties of WC-based coating reinforced by Fe-based amorphous alloys

摘要:

采用超音速火焰喷涂技术制备了WC-CoCr/铁基非晶复合涂层。比较研究了复合涂层和WC-CoCr的微观形貌、硬度、耐磨性能、高温氧化性能和腐蚀性能。XRD分析和SEM观察表明，复合涂层主要由WC相、W2C相和铁基非晶相组成。与WC-CoCr涂层相比，复合涂层的硬度有所降低，但是两者没有显著性差异。由于硬度下降，导致复合涂层的耐磨性能略低于WC-CoCr涂层。800℃高温氧化测试表明，复合涂层在800℃具有良好的热稳定性，这归因于氧化过程中生成了一层致密的氧化膜。此外，复合涂层在3.5%氯化钠溶液中的耐腐蚀性能也优于WC-CoCr涂层。

Abstract:

WC-CoCr/ Fe-based amorphous alloy composite coating has been prepared by high velocity oxygen fuel (HVOF) spraying. Microstructure, hardness, wear resistance, high temperature oxidation and corrosion resistance of the composite coating are comparatively studied with WC-CoCr coating. XRD analysis and SEM observation show that the composite coating is mainly composed of WC, W₂C and a Fe-based amorphous phase. In comparison with WC-CoCr coating, the hardness of the composite coating is slightly decreased, but there is no statistically significant difference between them. As a result of hardness decrease, the wear resistance of the composite coating is a little bit inferior to that of the WC-CoCr coating. Results of high temperature oxidation at 800 ^_oC proved that the composite coating exhibits excellent thermal stability, which is mainly attributed to the formation of a dense and uniform oxide layer during the high temperature oxidation test. Moreover, electrochemical test revealed that the corrosion resistance of the composite coating is better than that of WC-CoCr coating in 3.5 wt.% NaCl solution.