ASTM B480-88 pdf free.Standard Guide for Preparation of Magnesium and Magnesium Alloys for Electroplating.
Because of the low solubility of the tetrasodiunpyrophosphate, it is generally necessary to mix this solution iran elevated temperature from 70 to 85C.It is also advantageous to alternately add portions of the zinc sulfate andpyrophosphate. When these ingredients are completely dis-solved, add and dissolve the balance of the ingredients in thcorder given.Immerse the parts for 3 to 10 min in the solutionoperated at 79 to 85C and agitate mildly. Do not use glass orfiberglass equipment of any kind.Careful control is essentialfor best results. Maintain the pH between 10.2 and 10.4electrometric (glass electrode) measured at 25°C. (Warning—The glass electrode must be used with caution. Do not allowthe electrode to remain in contact with the zincate solution forprolonged periods. Inspect and test the electrode regularly toensure that no change has occurred from contact with fluorideion. Colorimetric (paper) methods may be used.However, thecolorimetric readings may vary 0.5 pH units.)
Plate the parts about 6 min.Cathode rod agitation issuggested. With either bath make electrical contact quicklywith initial current 5 to 10 A/dm2, then lower current to 1 to 2.5A/dm2.Rinse thoroughly in cold water. Dip in diluted acid (1 % by vol sulfuric acid  99 %by vol water). Rinse in cold water.Apply subsequent electrodeposits or autocatalyticnickel in accordance with standard commercial electroplatingpractice.3 Use plastisol-coated racks that are fitted with stainless steel or phosphor-bronze rack tips.Autocatalytic Nickel Plating Magnesium: Surface Conditioning -See 5.1.1 and 5.1.2, and 5.2.1-5.2.4.
Pickle in (1) chromic acid3 as directed in5.2.5.2 or in (2) phosphoric acid3(90 % by vol phosphoricacid 10 % by vol water) using a lead,glass，ceramic，orrubber-lined tank of polyethylene,polypropylene,or othersuitably corrosion resistant material.
Use a tank lined with polyvinyl chloride plastisol，bakedphenolic based enamels, polyethylene, polypropylene, or othersuitably resistant material. Use mild mechanical agitation.Immerse parts in nickel solution operated at 77 to 82C with apH range of 5.5 to 6.3, measured at 25C.The bath should befiltered either periodically or continuously.The use of a pumpwhich is sealess or designed for operation in fluoride and withelectroless nickel solution is recommended.To ensure adequatefiltration，the solution should be filtered in excess of 20 tankvolumes per hour through a 5-micron filter. The use of aplastic,magnetically coupled pump will eliminate problemswith shaft seals.ASTM B480 pdf download.