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以AZ31镁合金热喷涂铝涂层为研究对象,用自制的振动热扩散装置,进行一定温度热扩散或在热扩散的同时进行振动机械研磨处理,研究比较了振动热扩散对镁合金热喷铝涂层的影响。采用金相显微镜、扫描电子显微镜观察涂层表面、截面形貌,对涂层界面进行能谱分析,利用显微硬度计测量不同工艺下涂层与镁基体界面处硬度变化,利用X射线衍射分析涂层与基体界面处扩散区域相组成,用电化学工作站测得涂层极化曲线,通过盐水浸泡分析比较了不同工艺处理后镁合金的耐腐蚀性。结果表明:镁合金喷铝涂层经360~400℃保温2h热扩散或振动热扩散(机械研磨热扩散),在涂层与镁基体的界面处镁铝原子有不同程度的互扩散,并有镁铝Al12Mg17相生成,界面硬度有极大提高,振动热扩散使涂层明显致密化并形成连续析出相,能有效提高涂层的耐腐蚀性能。
Taking AZ31 magnesium alloy thermal sprayed aluminum coating as the research object, a self-made vibration thermal diffusion device was used to conduct thermal diffusion at a certain temperature or vibration mechanical polishing while thermal diffusion was carried out. The effects of vibrational thermal diffusion on the thermal spraying aluminum Effect of coating. The surface and cross-sectional morphology of the coating were observed by optical microscope and electron microscope. The interface of the coating was analyzed by energy dispersive spectroscopy. The hardness at the interface between the coating and magnesium matrix was measured by microhardness tester. The diffusion zone of the coating and the matrix interface was composed. The polarization curve of the coating was measured by electrochemical workstation. The corrosion resistance of the magnesium alloy after different treatment was compared by brine immersion analysis. The results show that the Mg-Al sprayed coatings have thermal diffusivity or vibrational heat dissipation (thermal mechanical diffusion) at 360 ~ 400 ℃ for 2h, and have different degrees of interdiffusion of Mg and Al atoms at the interface between the coating and Mg matrix. Magnesium aluminum Al12Mg17 phase generated, the interface hardness has greatly improved, the vibrational thermal dispersion of the coating was significantly densified and the formation of continuous precipitation phase, can effectively improve the corrosion resistance of the coating.