【摘要】 在交流条件硅酸钠溶液中利用微等离子体氧化技术合成了陶瓷涂层。通过XRD,EPMA分析了所得陶瓷涂层在不同层面上的相组成、微观结构及元素分布。由陶瓷涂层截面的背散射图看出陶瓷涂层较致密、与基体结合强度高。XRD分析结果显示,陶瓷涂层的最外层由莫来石及γ-Al2O3相组成,随着向陶瓷涂层内部的移动,莫来石的含量逐渐减少,α-Al2O3,γ-Al2O3相的含量逐渐提高,而且陶瓷涂层的颜色由白色逐渐变为黑色。硅元素在陶瓷涂层的外侧及陶瓷涂层与基体的交界处陶瓷涂层一侧含量较多,在陶瓷涂层中间含量少。而陶瓷涂层的硬度变化也出现了中间高,两侧低的分布情况。更多还原

【Abstract】 The surface modification of aluminum and its alloys using micro-plasma oxidation (MPO) technology is being increasingly investigated. MPO is a cost-effective plasma electrolytic process which can form ceramic coatings on aluminum and its alloys thereby increasing their wear resistance and corrosion resistance. In this work, the ceramic coatings are deposited from a Na2SiO3 solution using an alternating current power source. Phase composition as function of depth into the coating, microstructure and elemental distribution were investigated by XRD and EPMA(electronic Probe Microanalysis). It is seen from the back scattered electron micrograph that the ceramic coatings is compact, with good cohesion/adhesion between the substrate and the ceramic coatings. The XRD results show that outer layer of the ceramic coating consists of mullite and γ-Al2O3. In the ceramic coating to the substrate direction, the mullite content of the coating decreases, while the α-Al2O3 and γ-Al2O3 content increases. In the other hand, the colour of ceramic coating transforms from black to white. In the middle of the coating the Si content is lowest, and the microhardness is highest.更多还原