论文部分内容阅读
超音速火焰喷涂过程中产生的残余应力会限制涂层的厚度。在研究中,为了获得高质量WC-Co厚涂层,在超音速火焰喷涂过程中采用了干冰冲击技术,这主要是由于干冰冲击对涂层产生了高效冷却和机械锤平。本研究采用X射线衍射,扫描电镜和能谱能对粉末和涂层得微观结构和相分布进行表征。此外,本文对涂层的硬度、抗滑动摩擦等性能也进行了研究。最后我们得出结论,干冰冲击能有效地细化晶粒尺寸,提高涂层硬度,致密度和抗滑动摩擦性能。本研究采用超音速火焰喷涂和干冰冲击联合的工艺方法喷涂WC-Co粉末,以提高冷却效率和喷涂过程中的类喷丸效应。该方法也可以用来制备厚的WC-Co涂层。本文还研究了涂层的微观组织、相组成和摩擦磨损性能。
Residual stresses generated during supersonic flame spraying limit the thickness of the coating. In the study, in order to obtain a high quality WC-Co thick coating, a dry ice blasting technique was used in the supersonic flame spraying process, mainly due to the efficient cooling and mechanical hammer flattening of the coating due to dry ice impact. In this study, the microstructure and phase distribution of powders and coatings were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. In addition, the hardness of the coating, sliding friction and other properties are also studied. Finally, we conclude that dry ice impact can effectively refine grain size and improve coating hardness, density and anti-sliding friction properties. In this study, WC-Co powder was sprayed by a combination of supersonic flame spraying and dry ice blasting to improve the cooling efficiency and the shot-peening effect during spraying. This method can also be used to prepare thick WC-Co coatings. The microstructure, phase composition and friction and wear properties of the coatings were also studied.