| Abstract Scope |
The nanocrystalline coatings are often deposited to improve the wear resistance of the components. However, nanocrystalline metallic coatings often suffer high residual stresses, low strain hardening ability and lower toughness. To circumvent this problem, studies have focused on the development of gradient nanocrystalline materials with spatial gradients in composition and/or grain size. The present study involves the development of two-types of compositional gradient Ni-W coatings i.e., (a) multilayers and (b) linear gradient by using the pulse electrodeposition technique. The dense compositional gradient nanocrystalline Ni-W coatings were deposited by tailoring either the deposition bath chemistry or the deposition parameters. The compositional gradient Ni-W coatings have demonstrated substantially lower residual stresses and therefore improved wear resistance compared to their homogenous counterparts. The improvement in the properties is rationalized by correlating with the microstructural stability, lower residual stress and strain hardening ability of the compositional gradient Ni-W coatings. |