THE ELECTRODEPOSITION OF NI-P-AL2O3, DEPOSITS

Nickel phosphorus and nickel-phosphorus-alumina coatings have been ele ctrodeposited. X-ray diffraction studies show that both types of coati ng become more crystalline with the formation of Ni,P-3 and Ni upon he at treatment. The hardness of the as-plated and heat-treated coatings suggested that the as-deposited coatings containing alumina would be m ore wear-resistant than those containing only nickel and phosphorus, b ut with the reverse being true for the same deposits following heat tr eatment. The phosphorus content of deposits obtained by electrodeposit ion can be controlled by varying the phosphorous acid in the bath. (C) 1997 Elsevier Science S.A.