【摘要】 采用等离子喷焊方法在厚度为1mm的气门锥面制备了钴基合金涂层,观察了涂层的组织形貌,用X射线衍射仪分析了焊层的相结构,用电子探针分析了焊层的成分分布,测试了焊层的硬度与热稳定性。结果表明,喷焊强化层主要为铸态枝晶和细晶组成,在界面处存在明显的热扩散现象,喷焊层与基体之间呈冶金结合。喷焊层的稀释率为3%,且具有较高的硬度与良好的热稳定性。更多还原

【Abstract】 Co-based alloy coating were prepared on a 1 mm thickness tape-face valve by plasma spraying welding method. The microstructure of the welded layer was observed by optical microscope; the phase structure and component distribution of the welded layer were analyzed by X-ray diffraction (XRD) and electron probe respectively,the hardness and heat stability were tested. The results show that the coating is composed of cast dendrite and fine grain, and the bond between the coating and substrate is mainly metallurgical. The interface between coating and substrate exists obviously heat diffusion and the dilution rate of the layer is 3%. However, the welded layer has high hardness and good heat stability.更多还原