摘要
综述了传统锌合金压铸件防护精饰工艺的发展状况 ,提出了一种对锌合金压铸件进行化学镀镍处理的防护、精饰和改性方法。为了获得简单、实用、环保的工艺方法 ,通过正交试验选定了一种稳定的焦磷酸盐预化学镀镍溶液 ,在此溶液中既能获得均匀、致密、结合牢固的镍预镀层确保化学镀镍顺利进行 ;又保证了锌合金压铸件溶解失重小于 10 g/m2 。同时 ,研究了次亚磷酸钠含量、溶液 pH值及铝丝和尼龙绳不同装挂方法对溶液沉积速率的影响。结果表明 ,次亚磷酸钠含量对溶液稳定性作用显著 。
In connection with the review on the current state and development trend of conventional protection and finishing technology for zinc alloy die castings, it was suggested to use electroless nickel plating as a superior method for the protection, finishing, and modification of zinc die castings. Thus a pyrophosphate electroless strike plating solution was selected making use of orthogonal tests in the pursuing of a simple, practical, and environmentally acceptable protecting technology for the zinc die castings. Moreover, the influences of NaH_2PO_2 content, pH value, and different racking modes with aluminum wire and nylon cord on the deposition of the pre plated Ni coating and the electroless Ni coating were investigated. As the results, it was feasible to prepare a pre plated Ni coating of good uniformity, compactness, and bonding strength with the substrate from the pyrophosphate electroless strike plating solution, which made it possible to smoothly carry out the following electroless nickel plating at a mass loss of the zinc die castings below 10 g/m^2. The NaH_2PO_2 content, pH value, and different racking modes all had certain effects on the deposition of the electroless Ni coating. Namely, the stability of the plating solution was closely related to the NaH_2PO_2 content, while the pre plated Ni coating was deposited at a faster speed in the strike solution when an aluminum wire racking other than a nylon cord racking was used.
出处
《材料保护》
CAS
CSCD
北大核心
2005年第1期34-36,共3页
Materials Protection
关键词
化学镀镍
锌合金压铸件
次亚磷酸钠
electroless nickel plating
zinc alloy die castings
NaH_2PO_2
