WC基涂层材料和制备工艺对其组织结构与性能的影响

Effect of WC Based Coating Materials and Fabrication Technology on the Structures and Properties

本文采用超音速火焰(HVOF)喷涂工艺制备了二种微米结构WC-10Co-4Cr及一种纳米结构WC-12Co金属陶瓷复合涂层;采用SEM、XRD等分析了涂层的组织结构;测量了涂层的显微硬度、孔隙率及开裂韧性;采用超声振动空蚀装置研究了涂层的抗空蚀性能,探讨了涂层空蚀机理。结果表明:由燃油型HVOF工艺制备的纳米WC-12Co涂层孔隙率最低,组织最细小,开裂韧性明显高于燃油型和燃气型HVOF工艺制备的微米WC-10Co-4Cr涂层;燃油型HVOF工艺制备的微米结构WC-10Co-4Cr涂层显示了最优异的抗空蚀性能,空蚀率仅为纳米WC-12Co涂层的1/3左右。

Two micro-structured WC-10Co-4Cr cermet coatings and a nano-structured WC-12Co cermet coating were deposited by High Velocity Oxy-Fuel spray（HVOF）,and the morphologies and structures of the coatings were analyzed by SEM and XRD. Porosity, microhardness and fracture toughness of the coatings were measured. Resistance of coatings to cavitation erosion was studied by ultrasonic vibration cavitation equipment and the cavitation mechanisms were explored. Results show that the nano-structured WC-12Co coating deposited by High Velocity Fuel spray had lowest porosity and the densest microstructure and fracture toughness was significantly higher than that of micron-structured WC-10Co-4Cr coatings. Although the micron-structured WC-10Co-4Cr cermet coating deposited by HVOF had more coarser particles than the nano-structured, it exhibited the most excellent resistance to cavitation erosion, and the cavitation erosion rate was approximately one third that of the nano-structured WC-12Co cermet coating.