摘要
x—射线衍射、能谱分析和SEM研究镍基碳化钨自熔性合金粉末火焰喷涂涂层,合金中碳化钨的含量对涂层的组织结构、孔隙率和硬度产生重要影响,进而使涂层的高温冲蚀磨损机制发生相应的变化。随涂层中碳化钨含量的增高,材料流失由基体塑性变形为主转变为碳化钨硬质相的脆性断裂为主,高韧性的Ni(γ)固溶体对碳化钨起支撑保护作用,弥散分布的硬质相改善了涂层的耐磨性。结果表明,Ni—WC35涂层具有最佳的抗高温冲蚀性能。
The eroded surfaces of Ni-WC coatings were examined by X-ray diffration, SEM and EDX. It has been found that tungsten carbide content in powders has been an important influence on the coating microstructure, poresity, hardness, as well as the erosion behavior of Ni-WC coating at room and elevated temperatures correspondingly. When tungsten carbide content in powders increases, erosion mechanism which is determined by large ammount plastic deformation in the substrate turned to be dominant by cracking of carbide. Disperse carbide phase which is supported by high toughness Ni-base solid solution improves wear resistance. It has shown that the coating with 35 percent tungsten carbide is possesed of better erosion resistance than others at high temperature.
