鋁基材鍍化學鎳最穩固的選擇-遠見化工

MetChem’s Electroless Nickel Process for Aluminum Alloy

HLHC and MetChem have focused on development and service in electroless nickel plating on aluminum for many years, provide excellent chemicals for processes from pre-treatment, nickel, to sealing. Deposit uniform deposition and strong adhesion even on heterogenous-substrate of aluminum/stainless steel. For various application to electroless nickel on aluminum likes hardness, corrosion resistance, brightness, or non-magnetic, HLHC present you the high reliable solution.


In purpose to reinforce the strength of aluminum alloy surface, likes hardness, wearability, or corrosion resistance, electroless nickel plating is widely applied on aluminum-based parts. However, aluminum is very easily oxidized in atmosphere, and those oxide will weaken the bonding strength between substrate and electroless nickel layer and causes deposition peeling or blister. So double zincate processes are used in typical pre-treatment to avoid oxidation on aluminum substrate. In addition, the probability of coating blister also is related to surface conditioning in pre-treatment process and initial plating of nickel. That’s why manufacturers need pay more attention on plating on aluminum than normal ferrous substrate.

According to the past study[1], the adhesion strength between aluminum substrate and electroless nickel deposition is depended on surface condition. Once the zincate is incompetent for parts, zinc layer will be thick with coarse grains, and affect electroless nickel plating. In addition, lots of pits might be created on substrate if surface is too rough then becomes defect to deposition adhesion. Furthermore, improper etching and desmut, or poor zincate coverage also cause deposition peeling with oxidation on substrate. These problems indicate clearly that preventing from oxidation on substrate in pre-treatment plays a key role in electroless nickel plating on aluminum alloy.



SEM on zincate-coated aluminum substrate[1]. It indicates clearly that large grains and pitting were formed by poor zincate process.



Those possible issues which deteriorate aluminum substrate in pre-treatment, are solved in MetChem’s electroless nickel process. Our neutral non-silicated soak cleaner SC-301 effectively removes light soils, fingerprints, oils and other shop dirt and leaves the surface free of water breaks. The acidic aluminum etchant A-130 provides a mild uniform etch on all aluminum alloys thus improves adhesion of electroless nickel deposition. And MetChem 500/520 Zincate process is a unique cyanide-free zincate that promotes excellent adhesion and pore free deposits of electroless nickel on a wide range of aluminum alloys.

Plating on heterogenous-substrate of aluminum/stainless steel is a difficult challenge because there is a big exactly difference in electroless nickel process between two materials, moreover, both aluminum and stainless steel are sensitive to oxidation in pre-treatment then create peeling or blister. The coating on heterogenous-parts is failed in the adhesion test if using conventional electroless nickel process; nevertheless, MetChem did it. Our brilliant electroless nickel plating satisfies the requirement of heterogenous part of aluminum/stainless steel, prevent oxidation from processes and perform awesome bonding strength on the hetero-junction. Passes adhesion test with thermal shock at 200C above, no peeling or blister. And has been applied to mass production of surface treatment on heterogenous parts.

In adhesion test with thermal shock on aluminum-stainless steel heterogenous-parts, blister was created with conventional electroless nickel process resulted from poor bonding between deposition and substrate. However, the heterogenous surface was exactly activated and plated by MetChem’s electroless nickel, no blister or peeling in the test.


HLHC has dedicated to serve and assure our clients with electroless nickel plating for many years. For all your needs in hardness, brightness, lubrication, corrosion resistance, solderability, or non-magnetic, we provide, completely customize electroless nickel processes, and add the value of your products.

[1]:https://doi.org/10.2320/matertrans.47.2518