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利用真空热压烧结炉在挤压态AZ61镁合金表面制备了平均粒径为41μm的Mg17Al12-1Er金属涂层。电化学测试结果表明,50μm及以上厚度的涂层耐蚀性基本一致,使镁合金的自腐蚀电位提高500mV以上,自腐蚀电流密度降低2个数量级,极化电阻提高1个数量级,100μm厚的涂层对镁合金基体防护性最佳。在阳极极化的快速析氢条件下,氢气产生时的高压可以将涂层颗粒从涂层中挤出,而在3.5%NaCl溶液中析氢速度较慢,但是在涂层表面会形成氢致裂纹,导致涂层脱落,最终使其失去对基体的保护作用。
The Mg17Al12-1Er metal coating with an average particle size of 41μm was prepared on the surface of extruded AZ61 magnesium alloy by vacuum hot-pressing sintering furnace. The results of electrochemical tests showed that the corrosion resistance of the coatings with the thickness of 50μm and above is basically the same, the self-corrosion potential of the magnesium alloy is increased by more than 500mV, the self-corrosion current density is reduced by two orders of magnitude, the polarization resistance is increased by one order of magnitude, Coating of magnesium alloy matrix protective best. Under the conditions of rapid anodic polarization, the high pressure of hydrogen can expel the coating particles out of the coating, while the hydrogen evolution rate is slow in 3.5% NaCl solution, but hydrogen-induced cracks are formed on the coating surface, Cause the coating to fall off and eventually lose its protective effect on the substrate.