HEAT TREATING ELECTROLESS NICKEL COATINGS

Heat treatment of electroless nickel coatings, chemically deposited nickel and phosphorus (7 to 10.5%), produced no microstructure changes below 750 deg F. Above 750 deg F, precipitation and agglomeration were detected. The maximum hardness (1000 dph) was found to be independent of phosphorus content and occurred during the formation of an interim lattice from the amorphous structure of the as-deposited plate. (C.J.G.)