Evaluation of Hardness for Electroless Ni-P Coatings

Abstract

One of the outstanding characteristics of EN coatings is their high hardness. There are three major parameters affecting the hardness of these coatings, namely, phosphorus content, time, and the temperature. In the present paper, Ni-P coatings with 8 and 10% P were deposited on iron steel. The morphology, structure, microhardness of the Ni-P coating, were analyzed using X-ray powder diffraction (XRD) and Vickers hardness tests. The relation of chemical composition and microstructure with mechanical properties of Ni-P coatings is presented. The phosphorus contents, the crystallization, and the incorporation of hard particles in the coatings change the values of hardness.