Abstract: A process is provided for enhancing the wear resistance of aluminum and other materials by depositing on the substrate a nickel, cobalt, phosphorous alloy coating using an electroless plating bath to provide a plated alloy having a cobalt content of at least about 20% by weight and a % Co/% P weight ratio of at least about 5. A preferred bath contains an effective amount of glycolic acid or salts thereof. The alloy deposit is preferably plated over a zincated aluminum substrate.

Abstract: A process is provided for plating zinc die cast substrates with an electroless nickel coating comprising depositing an electrolytic zinc layer on the substrate followed by depositing a first electroless nickel layer on the electrolytic zinc layer using a first alkaline electroless nickel bath and then depositing a finish electroless nickel layer on the first electroless nickel layer using an acidic electroless nickel bath. In a preferred embodiment, a second electroless nickel layer is deposited on the first electroless nickel layer using a second alkaline electroless nickel bath. It is preferred that at least one and preferably all of the electroless nickel baths contain an effective amount of antimony ions to enhance bath stability and metal to metal adhesion. Mechanical cleaning of the zinc die casting before plating is preferred.