Abstract
The ternary Ni-W-P alloy coatings were deposited by electroless plating on 420 stainless steel to evaluate the thermal property and related mechanical characteristics of the coating assemblies. The thermal stability of electroless Ni-W-P deposits, analyzed by differential scanning calorimetry (DSC), could be enhanced by the co-deposition of tungsten as compared to binary electroless Ni-P films. The phase and composition of Ni-W-P and Ni-P were evaluated by X-ray diffraction technique and electron probe microanalysis, respectively. The co-deposition of tungsten enabled the deposits to exhibit an amorphous structure with lower phosphorus content. Adhesion strength of the deposits on the substrates were assessed by a scratch test. The introduction of the tungsten in the Ni-P coating effectively reduced the linear crack length and delayed the cracking formation. Surface hardness of binary alloy coating could be modified with the introduction of the tungsten element. © 2001 Elsevier Science B.V. All rights reserved.