镁合金表面纳米ZrO_2涂层的制备及其性能研究

Preparation and properties of nano ZrO_2 coating on magnesium alloy

为提高镁合金的耐磨耐蚀性能,采用大气等离子喷涂技术在AZ80镁合金表面制备纳米ZrO_2涂层。利用SEM分析纳米喷涂粉末形貌和涂层显微结构,用球盘式摩擦磨损实验机考察涂层的摩擦磨损性能,并通过电化学测试和盐雾腐蚀试验测试涂层耐蚀性能。结果表明:大气等离子喷涂纳米ZrO_2涂层与镁合金基材的结合强度达到(28±6)MPa,显微硬度为(840±62)HV,磨损率为3.3×10^(-5)mm^3/(N·m),其耐磨性较传统的微米ZrO_2涂层提高1倍,较镁合金基材提高1个数量级。封孔后的纳米ZrO_2涂层在200 h盐雾腐蚀试验后未出现明显的腐蚀迹象。

In order to improve the wear and corrosion resistance of magnesium alloy, nano ZrO2 coating was deposited on AZ80 magnesium alloy substrate by plasma spraying technology. The SEM was used to characterize the morphology of nano feedstock powders and as-sprayed coating. The friction and wear properties of the coating were investigated by a ball on disk tribometer. The electrochemical and salt spray tests were also conducted to characterize the corrosion performance of as-sprayed coatings. The results indicate that high quality nano ZrO2 coating can be deposited on AZ80 magnesium alloy by plasma spraying technology. The bonding strength of nano ZrO2 coating is （28±6） MPa and its microhardness is （840±62）HV. The wear rate of nano ZrO2 coating is only 3.3 × 10^-5 mm^3/（N · m）, which demonstrates that the wear resistance of plasma sprayed nano ZrO2 coating is improved by one order of magnitude than that of magnesium alloy substrate. After 200 h salt spray test, the sealed nano ZrO2 coating shows no evidence of corrosion.