摘要
针对高硅铸铝件在组成、组织与性能上的特点 ,研究了 8种高硅铝合金镀前浸锌液。用扫描电镜 (SEM )观察了 8种不同的浸锌液配方浸锌后试片的表面浸锌膜的微观形貌 ,测定了浸锌后镀镍层与试片的结合力 ,优选了能获得良好结合力的最佳浸锌液配方。并研究了随浸锌时间的增加 ,锌晶核的析出与成长的过程。结果表明 ,当氢氧化钠 14 0 g/L、氧化锌 14～ 2 0g/L、氯化镍 1.5g/L时 ,试片镀镍后结合力良好。发现浸锌液能够溶解铝合金部分组织 ,并在铝表面造成孔洞 ,这种孔洞对镀层起着锚链作用。
In the light of the features of high Si Al alloy castings in composition, texture and performance, eight zinc dipping solutions used for high Si Al cast alloy are studied. The optimum dipping solution, which can result in good adhesion, is selected through observing the micromorphology of the zinc film surface of eight specimens dipped in eight different solutions by SEM, and by testing the adhesion of nickel coating to the substrate dipped with zinc. The procedure of the deposition and growth of zinc nucleus as time goes by during zinc dipping are also studied. The results show that a good adhesion can be obtained for the specimen following Ni plating when NaOH is 140 g/L, ZnO 14～20 g/L, NiCl 2 1.5 g/L in the solution. It is found that zinc dipping solution can dissolve part of Al alloy texture, and create holes in Al surface, which play an anchor chain role for nickel coating. The uniform dispersion of holes in Al alloy surface and high scattering of fine zinc crystals are the prerequistite for good adhesion.
出处
《电镀与环保》
CAS
CSCD
2002年第5期1-4,共4页
Electroplating & Pollution Control
