激振抛磨对ZM6镁合金航空机匣表面形貌及耐腐蚀性能的影响

Effect of vibratory polishing on surface morphology and corrosion resistance of ZM6 magnesium alloy for aviation casing

[目的]激振抛磨技术具有加工效率高、操作灵活、适用性广等优点,在航空航天零部件制造领域得到广泛应用。目前有关激振抛磨处理对ZM6镁合金航空零部件表面形貌及耐蚀性影响的研究报道还较少。[方法]采用自行研发的激振抛磨实验平台,对取自ZM6镁合金低压砂型铸造航空机匣的样块进行加工。对比了激振抛磨前后ZM6镁合金的表面形貌、粗糙度、元素组成及耐蚀性。[结果]激振抛磨处理后ZM6镁合金的表面形貌得到显著改善,表面粗糙度降低,裂纹和孔隙被去除,表面氧元素的原子分数降低了49.0%,基体元素的原子分数增大,耐蚀性显著提高。[结论]激振抛磨后ZM6镁合金的耐蚀性之所以提高,主要与其表面粗糙度的降低及表面致密均匀氧化膜的生成有关。

[Introduction]Vibratory polishing technology is widely used in the manufacturing of aerospace components due to its high efficiency,flexibility,and broad applicability.However,there are relatively few studies about the effect of vibratory polishing on the surface morphology and corrosion resistance of ZM6 magnesium alloy aerospace parts.[Method]A homemade vibratory polishing experimental platform was used to treat ZM6 magnesium alloy,which is the material of an aerospace engine casing made by low-pressure sand casting.The surface morphology,surface roughness,elemental composition,and corrosion resistance of ZM6 magnesium alloy before and after vibratory polishing were compared.[Result]After vibratory polishing,ZM6 magnesium alloy showed the following changes:significant improvement in surface morphology,decrease in surface roughness,removal of cracks and pores,a 49.0%decrease in atomic fraction of oxygen,an increase in atomic fraction of substrate elements,and a great improvement in corrosion resistance.[Conclusion]The improvement of corrosion resistance of ZM6 magnesium alloy after vibratory polishing is mainly related to the reduction of its surface roughness and the generation of compact and uniform oxide film on the surface.