用于大型船舶螺旋桨再制造的冷喷涂Cu402F涂层

Cold Sprayed Cu402F Coating for Large Marine Propeller Remanufacturing

针对大型船舶螺旋桨再制造的需求,采用冷喷涂技术在9442镍铝青铜上制备厚度200~300μm较为致密的Cu402F涂层。使用显微硬度测试仪、电化学工作站、磁致伸缩超声振动仪和摩擦磨损试验机观察并测试涂层的微观形貌、显微硬度、耐腐蚀性能、抗空泡性能及耐磨性能。结果表明:涂层的显微硬度为289 HV0.2,较基体的显微硬度提高了17%。涂层的耐腐蚀性能略有降低,但涂层表面可以形成更为稳定的Cu2O钝化膜,达到保护基体的目的。涂层的抗空蚀性能低于基体,细小气泡持续在涂层表面瞬间溃灭会导致涂层孔隙率持续增加,使得涂层在空泡腐蚀后期的抗空蚀能力减弱。涂层在大气与模拟海水中耐磨性能均优于基体,涂层表面的孔隙收容了磨屑,起到了一定减磨作用。

Aiming at the demand of large marine propeller remanufacturing, compact Cu402F coating of thickness of 200？300 μm was deposited on 9442 nickel aluminum bronze by cold spray. Morphologies, microhardness, corrosion resistance, cavitation resistance and tribological properties of the coating were tested by microhardness tester, electrochemical work station, magnetostrictive ultrasonic vibration meter and friction wear machine. The results show that the average microhardness of the coating is 289 HV0.2, which is higher than that of substrate by 17%. Corrosion resistance of the coated substrate degrades slightly while a stable Cu2O passivation film is formed on the surface of the coating. Cavitation resistance of coating is worse than that of the substrate, and caviation erosion rate of the coating continuously increase as the result of constant tiny bubbles collapsed and perished on the surface of the coating. Cavitation resistance of the coating weakens during the later period of cavitation erosion test. In the air and simulated seawater, corrosion resistance of the coating is better than that of the substrate. The friction coefficient of the coated sample is smaller than that of the substrate, possibly due to embedding of eroded dusts into the pores of the coating.