高锌镁合金化学镀镍磷初始沉积特征的研究  

Study of Initial Deposition Characteristics of Electroless Ni-P Coating on a Magnesium Alloy of

作　　者：曹文博[1] 任晨星[1] 关绍康[1] 

机构地区：[1]郑州大学材料科学与工程学院,河南郑州450002

出　　处：《材料保护》2006年第2期11-13,共3页Materials Protection

摘　　要：化学镀Ni-P能提高镁合金的耐蚀性。采用金相观察、X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱(EDS)等技术研究了铸态和固溶态Mg-8Zn-4Al合金化学镀Ni-P合金初始沉积的特点。结果表明由于镁基体中α固溶体,(Al2Mg5Zn2),τ[Mg32(Al,Zn)49]相的组成元素存在差别,造成了相间的电极电位存在差异,初生的镍离子优先在相和τ相上沉积;随后以最先沉积的点为中心向四周扩展,以胞状形式生长;经过固溶的Mg-8Zn-4Al合金组织主要为过饱和α固溶体,相和τ相析出效果不明显,镍离子的初始沉积变得较为均匀,沉积速度有所减缓。With a view to the significance of magnesium and its alloys in engineering and the effectiveness in increasing their corrosion resistance using electroless Ni-P plating,metallography,X-ray diffractometry,scanning electron microscopy,and energy dispersive spectroscopy were used to study the initial deposition characteristics of electroless on Mg-8Zn-4Al alloy of as-cast and solid-dissolved states.Results showed that the initial deposition of the Ni ions was highly dependent on the composition and tissue of the Mg alloy matrix.Namely,for the as-cast Mg alloy composed of α-solid solution,(Al-2Mg-5Zn-2),and τ[Mg- 32 (Al,Zn)- 49 ] phases,the Ni ions initially preferentially deposited at the (Al-2Mg-5Zn-2) and τ[Mg- 32 (Al,Zn)- 49 ] phase regions,owing to the differences in the electrode potentials; then the deposition continued and expanded to the nearby regions around the initially deposited spots,which allows the growth of the electroless Ni-P coating in a cell-like form.Contrary to the above,the Ni ions relatively uniformly deposited on the solid-dissolved Mg-8Zn-4Al alloy mainly composed of saturated α-solid solution at a slower plating rate as compared with that on the as-cast Mg alloy,which was related to the insignificant precipitation of the  and τ phases in the solid-dissolved Mg alloy matrix.

关 键 词：化学镀 Mg-8Zn-4Al合金 NI-P合金镀层 沉积特征 

分 类 号：TQ153.2[化学工程—电化学工业]