中文摘要：

以微米WC-12Co、纳米WC-17Co和WC-23Co三种团聚烧结粉末为原料，进行冷喷涂沉积涂层实验，通过扫描电镜、x射线衍射仪分别分析了涂层的组织结构和相结构，运用压痕法测定了涂层的显微硬度、弹性模量和断裂韧性，并通过销一盘磨损实验测定了涂层的耐磨损性能。实验表明，三种粉末所沉积的WC—Co涂层均具有致密的组织结构，涂层保持与原始粉末相同的相结构，黏结相co由于强烈塑性变形发生了同素异构转变，涂层组织无传统层状结构，WC硬质相发生了局部流动和再分布。对于纳米WC—Co涂层，随着黏结相含量增加，涂层硬度和弹性模量降低、断裂韧性增加，相对于316L不锈钢，冷喷涂WC—Co涂层表现出了优异的耐磨损性能，涂层磨损失效机理主要为磨粒对涂层的切削作用。

英文摘要：

Three kinds of WC-Co coatings were prepared by cold spraying （CS） of nanometer WC- 17Co, WC-23Co and micrometer WC-12Co powders. The microstructure and phase structure were an- alyzed by scanning electron microscope （SEM） and X-ray diffraction （XRD）. The microhardness, e- lastic modulus and fracture toughness of three kinds of the cold sprayed WC-Co coatings were investi- gated using microharder tester based on indentation toughness measurements and the wear perform- ance of three coatings were tested on a pin on disk tester. It was revealed that three cold sprayed WC- Co coatings have dense microstructure and similar phase structure with that of feedstock powder. The allotropie transformation of metal Co occurred due to its intensive plastic deformation. The coatings have no lamellar structure characteristics of conventional thermal spraying coating and the WC hard phase in the coatings flow and redistribute in local area. Moreover, the mierohardenss and elastic modulus of coatings decrease and fracture toughness increase with increasing binder phase content. Compared to 316L stainless steel, the cold sprayed WC-Co coatings exhibit excellent wear resistance and the wear mechanism is mainly the micro-cuts effect of abrasive particle on the coating surface.