15CrMnMoVA钢磁控溅射镀铝防护层耐腐蚀性能

采用磁控溅射技术,在15CrMnMoVA钢上镀覆一层纯铝防腐蚀薄膜。利用盐雾机、电化学测量仪、扫描电镜和能谱仪对比基体和铝涂层样品的耐腐蚀性能,同时分析偏压、靶电流、沉积时间等因素对涂层耐腐蚀性能的影响。结果表明,铝膜厚度为8.2μm的样品,铝膜层晶粒均匀,大小为1～2μm、膜/基界面平整、结合良好,其中基体与膜层界面处致密的过渡层对提高样品的耐腐蚀性作用显著;在中性盐雾气氛中,516h出现红锈;Al膜沉积时间为1h的样品,其自腐蚀电流比基体低2个数量级,达到icorr=-6.53×10-8 A,能有效提高基体的耐腐蚀性,膜层在中性盐雾腐蚀气氛下失效方式为逐层失效;薄膜沉积过程中,提高负偏压、靶电流和镀膜时间,均能提高膜层的质量。

Corrosion Resistance of Aluminum Film on 15CrMnMoVA Steel by Magnetron Sputtering

Aluminum film was prepared by magnetron sputtering technology on 15CrMnMoVA steel surface.Surface and cross-section images of aluminum film were observed with a scanning electron microscope(SEM).The corrosion behaviour of the 15CrMnMoVA substrate and Al-coated specimens was investigated and compared by potentiodynamic polarisation,a neutral salt spray(NSS) test and energy dispersive X-ray spectroscopy(EDS).The variaty of corrosion resistance of aluminum film under different bias voltages,target currents and depositional times was analyzed.The results indicate that for the specimen with aluminum film of 8.2 μm,fine crystals sized 1-2 μm uniformly deposite on the surface of the substrate,strong adhesion exists on the interface,and the compact transition layer existing in the interfacial zone between the film and the substrate plays an effective role in resistance to corrosion.At neutral salt spray atmosphere,red rusty corrosion products appeared after 516 h.For the specimens with the depositional time of one h,the corrosion current densities were approximately two orders smaller than that of the bare 15CrMnMoVA steel,to-6.53×10-8 A,which effectively improved the corrosion resistance,and the style of the invalidation of the film is layer by layer.During the process of deposition,the quality of the film can be improved by properly improving the bias voltage,target current and depositional time.