微纳米 涂层在 介质中的抗泥沙冲蚀性能研究

采用超音速火焰喷涂 (HVOF) 工艺制备了微纳米、 纳米和普通结构 WC-10Co4Cr 金属陶瓷涂层， 测量了涂层的显微硬度、 孔隙率和开裂韧性， 分析了三种 WC-10Co4Cr 涂层在 3.5wt% NaCl 溶液中的腐蚀电位和腐蚀电流密度， 研究了喷涂层在 NaCl 介质中的抗泥沙冲蚀性能， 并探讨了涂层在 NaCl 介质中的泥沙冲蚀机理。 结果表明： 微纳米 WC-10Co4Cr 涂层具有最优异的电化学性能； 相比于纳米、 微米涂层， 微纳米涂层的抗泥沙冲蚀磨损性能分别提高了 38% 和 78%。 微纳米 WC-10Co4Cr 涂层致密的组织结构、 高显微硬度 (1126HV0.3) 和高开裂韧性 (4.66MPa·m1/2) 有效减弱了泥沙冲蚀过程中的机械冲刷作用和电化学腐蚀作用。

Research on Slurry Erosion Resistance of Micro-nanoWC-10Co4Cr Coatings in NaCl Solution

Micro-nano, nano and conventional structured WC-10Co4Cr cermet coatings were deposited by High Velocity Oxy-Fuel spray (HVOF). The microhardness, porosity and fracture toughness of the coatings were measured. The corrosion potential and corrosion current density of the three WC-10Co4Cr coatings in 3.5 wt% NaCl solution was analyzed. Furthermore, resistance of slurry erosion of the coatings in NaCl solution was studied and the slurry erosion wear mechanisms of the coatings were explored. The results show that the micronano WC-10Co4Cr coating possesses the most excellent corrosion resistance in NaCl solution. Compared with the nano and micro coatings, the resistance of slurry erosion of the micro-nano coatings is enhanced by 38% and 78%, respectively. The dense microstructure, high microhardness and high fracture toughness of the WC-10Co4Cr micro-nano coating effectively reduce the mechanical erosion and electrochemical corrosion effects during the slurry erosion process.