涂层厚度对AZ91D镁合金WC涂层性能影响研究

采用JP-5000超音速火焰喷涂技术在AZ91D镁合金表面喷涂WC-10Co4Cr涂层。利用扫描电子显微镜、X射线衍射仪、显微硬度计等设备和浸泡腐蚀实验来分析WC涂层的组织结构和性能。结果表明：WC涂层均匀、致密,孔隙较少,涂层与基体结合紧密,无裂纹,无剥离;WC发生分解形成W2C,分解率与火焰作用时间有关;随涂层厚度的增加,涂层的显微硬度有增大的趋势;WC涂层提高了镁合金的耐腐蚀性。

Effect of coating thickness on properties of WC/AZ91D Magnesium alloy

In this study,WC-10Co4Cr coating is used to protect AZ91D Magnesium alloy by JP-5000 high velocity oxy fuel（HVOF）.In order to study the effect of spray parameters at interface between the surface of AZ91D Magnesium alloy and the coating,the SEM,EDS,XRD and other analytical methods were used for material structure and composition test.Experimental results showed that WC coating was uniform,compact,lower porosity and no cracks.There was a new phase of W2C existed in the coating after the decomposition of WC in spray process.Its decomposition of rate was effected by the spraying time.The micro-hardness of coating had an increasing tendency as its thickness was increased.Corrosion test showed that WC coating could effectively isolate the erosion from the environment to protect the Magnesium alloy.