喷射电沉积技术制备Co-Cr_3C_2复合镀层的工艺优化

Process Optimization of Preparing Co-Cr_3C_2 Composite Coatings by Jet-electrodeposition

为提高微米级硬质陶瓷颗粒在金属基复合镀层的含量,制备性能优异的防护性镀层,采用喷射电沉积的方法在直流电压下制备了Co-Cr_3C_2复合镀层,利用控制变量法探讨了电流密度、固体颗粒用量、镀液流量以及喷枪移动速度等对镀层中颗粒含量及镀层性能的影响,并分析了各因素的影响机理。同时,分别采用能谱仪、显微硬度计和摩擦磨损试验机对复合镀层的成分、硬度和摩擦因数进行分析,最终确定了制备该复合镀层的较优工艺参数。结果显示:喷头移动速度对颗粒复合量的影响最为显著;颗粒复合量越大,复合镀层硬度越高、摩擦因数越低;在较优工艺参数下制备的Co-Cr_3C_2复合镀层的Cr_3C_2颗粒含量高达23.6%。

In order to improve the content of micro-sized ceramic particles in metal matrix composite coating, and to enhance the performance of protective coatings, the Co-Cr3C2 composite coatings were prepared by j et-electrodeposition using DC voltage. The influences of the current density, the concentration of particles in solution, the flow of solutions and spray gun speed on the particle content as well as coating properties were investigated, respectively. The mechanism of the influence of various factors was also discussed. The composition, hardness and friction coefficient of composite coatings were analyzed by EDS, a microhardness tester and a friction and wear testing machine. Then the optimal parameters for preparing the composite coating was determined. The results show that the gun movement speed is the most significant influence on the mass fraction of Cr3C2 in the coating. Moreover, the hardness is higher and the friction coefficient is lower with higher content of particles in composite coating. The content of Cr3C2 particles reaches 23.6% in composite coating which is obtained with the optimal parameters.