烤瓷用镍铬合金阳极钝化处理的表面氧化膜研究

目的 分析烤瓷用镍铬合金在上瓷前进行阳极钝化处理对其表面氧化膜的形貌、厚度及主要金属元素氧化程度的影响。方法 将烤瓷用镍铬合金制成10个试片，随机分成2组，每组5片。1组经阳极钝化处理，1组不经处理作为对照。每组随机抽取2片进行扫描电镜观察，其余3片采用X射线光电子能谱仪和俄歇电子能谱仪进行表面氧化膜分析。结果 经阳极钝化处理的试片表面发生了轻度的选择性溶解，增加了金属的表面积，所形成的氧化膜厚度是空白对照组的1.72倍；氧化膜中铬、镍、钼等主要元素氧化成离子的比例较高，铬尤为明显。结论 采用阳极钝化法处理镍铬合金表面，形成的氧化膜较薄，表面结构均一，操作可重复性强，是烤瓷前金属表面处理的新方法。

Research of the Surface Oxide Film on Anodizing Ni-Cr Porcelain Alloy

OBJECTIVE: To study the shape, thickness and oxide percentage of major metal element of oxide film on Ni-Cr porcelain alloy after anodizing pretreatment. METHODS: 10 samples were made and divided into 2 groups at random. Then after surface pretreatment, the oxide films of two samples of each group were analyzed using electronic scanning microscope. The rest 3 samples were measured by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). RESULTS: Lightly selective solution appeared because the different component parts of the alloy have dissimilar electrode, whose dissolve velocity were quite unlike. The sample's metal surface expanded, so the mechanical interlocking of porcelain and metal increased bond strength. The thickness of oxide film was 1.72 times of the control samples. The oxide percentage of major metal elements such as Cr, Ni and Mo were higher, especially Cr. It initially involved the formation of a thin oxide bound to the alloy and second, the ability of the formed oxide to saturate the porcelain, completing the chemical bond of porcelain to metal. CONCLUSION: The method of anodizing Ni-Cr porcelain alloy can easily control the forming of oxide film which was thin and its surface pattern was uniform. It is repeated and a good method of surface pretreatment before firing cycle.