WC-CoCr涂层热震及高温抗氧化性能

Thermal Shock and High Temperature Oxidation Resistance Properties of WC-CoCr Coating

采用超音速火焰喷涂技术在45钢表面制备了WC-CoCr涂层,在空气环境中对涂层进行高温氧化试验和热震试验,借助SEM、XRD和电子天平分别分析了涂层表面的微观形貌、氧化前后产物相组成及涂层增重。结果表明:HVOF制备的WC-CoCr金属涂层的组织致密、孔隙率低。该涂层经600℃静态空气氧化后,在涂层表面生成了CoWO_4、WO_3、Cr_2O_3等氧化产物,这些氧化物可阻止氧化的进一步发展,提高了涂层的抗氧化能力,涂层没有发生剥落。WC-CoCr涂层具有优异的抗氧化和热震性能。

WC-CoCr coatings were prepared on 45 steel by HVOF, and the high temperature oxidation test and thermal shock test of the coating in air atmosphere were carried out. The microstrueture, phase of the coating before and after oxidation test and the mass gain of the coating were examined by SEM, XRD and electro balance. The results show that the microstructure of the coating prepared by HVOF is dense and the porosity is low. The surface of the coating after oxidation at 600 ℃ in static air generates the oxidation production of CoWO4,WOa,Cr203. The oxidation product can furtherly hinder the oxidation of the coating, and then, the oxidation resistance properties of the coating improve. The coating does not peel off. WC-CoCr coatings have good oxidation resistance and thermal shock performance.