Metal Finishing Guide Book

2011-2012 Surface Finishing Guidebook

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Step Alkaline soak cleaner Rinse in demineralized water Chromic acid or phosphoric acid pickle Rinse in demineralized water Phosphoric acid–fluoride etch Rinse in demineralized water Fluoride-containing "zincate" Rinse in demineralized water Copper cyanide strike Rinse in demineralized water Electroless nickel plating bath to desired thickness Table 1: Common Procedure for Applying EN to a Magnesium Substrate Step Alkaline soak cleaner Rinse in demineralized water Deoxidize in mild acid solution Rinse in demineralized water Temperature 180–200°F Ambient Table 2: Zincate-/stannate-free Pretreatment Process for EN Plating processed part for several days before going into the electroless nickel bath is pos- sible. One simply needs to soak the part in demineralized water for about half an hour to reactivate the bonding surface before going into the electroless nickel bath. If you only want to paint the part, the surface is excellent for painting. ALUMINUM Every aluminum alloy will have certain unique cleaning problems associated with it and, as such, it is not possible to give an all-encompassing cleaning process for all aluminum alloys. It can be stated that plating on aluminum will in almost every instance require a zincate or stannate process after cleaning and deoxidization to maintain a receptive surface.6 164 Duration 5–8 minutes 15–30 seconds Temperature 180–200°F Ambient Ambient 155–160°F 130–140°F Duration 3–5 minutes 30–60 seconds 1–2 minutes 3–15 minutes 6–8 minutes

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