纯Cr涂层厚度对涂层微观结构及抗高温氧化性能的影响

Effect of Cr Layer Thickness on Microstructures and High Effect of Cr Coating Thickness on Microstructures and High Temperature Oxidation Resistance

采用磁控溅射技术,在锆合金表面制备纯Cr金属涂层.探索纯Cr涂层厚度对抗高温氧化性的影响。利用扫描电镜分析涂层表面与截面形貌;采用X射线衍射对涂层进行物相分析;利用划痕仪分析涂层厚度对膜基结合力的影响;研究不同厚度的纯Cr涂层对涂层抗高温氧化性能影响。结果表明:随着涂层增厚,涂层表面孔洞数量呈越少趋势;涂层厚度不会影响涂层的择优取向与晶粒尺寸大小;涂层厚度为5.5μm,涂层的结合力最大;涂层的氧化增重随着涂层增厚,先减小后增加,涂层厚度为5.5μm,氧化增重最小。

Herein,we reported thesurface modification of Zr alloy with Cr coatings grown by magnetron sputtering. The effect of the thickness of Cr-coating on the microstructures and high temperature oxidation resistance was investigated with scanning electron microscopy,X-diffraction and conventional mechanical probes. The results show that the Cr-coating thickness strongly affected the oxidation resistance,microstructures and interfacial adhesion. To be specific,as the thickness increased,the oxidation resistance changed in an increase-decrease mode,accompanied by little variation inthe average grain-size and preferential growth orientation,possibly because of the decrease of pore density. A thickness of 5. 5 μm resulted in the minimum oxide gain and the strongest interfacial adhesion. In addition,oxidation of a thick Cr-coating significantly increased the density of cracks due to an increased residue stress.