铍铝合金微弧氧化膜的微观结构、成分及性能

目前国内尚未开展铍铝合金的微弧氧化技术研究。采用微弧氧化技术在粉末冶金铍铝合金材料表面原位生长出一层氧化膜;采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)对氧化膜层的结构、形貌和成分组成进行表征分析。结果表明:氧化膜层平滑、致密,表面分布着Be、O、Al等元素。在微弧放电的高温下,氧化膜层的形成是各个反应过程的综合结果。所得氧化膜层的厚度均值为11.221μm,从氧化膜表层到基体方向,O、Si、P元素的含量有明显减少的趋势,而Al元素和Be元素含量的变化趋势则刚好相反。膜层有一定的结合强度、硬度和较小的表面粗糙度,并且能耐114 h的盐雾试验,击穿电压高于1 000 V。

Micro-Structure,Composition and Performance of Micro-Arc Oxidation Coating on Beryllium Aluminum Alloy

Oxidation coatings were in-situ prepared on the surface of powder metallurgy beryllium aluminum alloy material by micro-arc oxidation technology.The scanning electron microscope (SEM),energy disperse spectroscopy (EDS) and X-ray diffraction were used to characterize and analyze the structure,morphology and chemical composition of the oxidation coating.Results showed that the oxidation coating was smooth and dense,and there were Be,O,Al and other elements distributed on the surface.Under the high temperatures from micro-arc discharge,the formation of oxidation coating was the comprehensive result of various reactions.Moreover,the average thickness of prepared oxidation coating was 11.221 μm.The contents of O,Si,P elements decreased obviously from the surface of coating to the substrate,while those of Al element and Be element increased.Besides,the oxidation coating possessed a certain bonding strength,hardness and lower surface thickness,and could withstand the salt spray test for 114 h.