Diamond nanoparticles as a dispersion phase in Ni-P/diamond composite coatings produced by chemical reduction

Nanoparticles are a group of materials that have become increasingly important in recent years. In surface engineering, nanoparticles can be used as a dispersion phase incorporated into a metal matrix to improve the properties of composite coatings. By selecting the type of particles and their shape, the properties of the final products can be modified. The use of carbonaceous materials with nanometric dimensions appears to be of particular interest. Several papers [1-4] have been published that study the incorporation of particles such as graphene, graphite, carbon nanotubes, or diamond. The latter, due to its very high hardness, can significantly improve the mechanical and tribological properties of metal coatings.

This paper presents the results of a study on Ni-P/diamond composite coatings as well as Ni-P coatings without embedded particles for comparison. The coatings were produced by a chemical reduction from multi-component bath solutions on steel substrates. Characterization of the nanodiamond used is presented in this study (SEM, XRD). The morphology and surface topography were investigated by SEM, light microscopy, and measurements of roughness parameters. The structure of the investigated coatings was characterized by XRD. The hardness of the produced coatings was tested using the Knoop method (HK0.01). Tribological tests were conducted using the ball-on-disc method. The adhesion of the developed coatings to the substrate was tested using the scratch test method.

The incorporation of nanodiamonds into an alloyed Ni-P matrix alters the morphology and surface topography of the materials produced. Composite coatings with diamond exhibit higher hardness and a lower coefficient of friction compared to Ni-P coatings without embedded particles.

Funding: The presented research was financed by the earmarked grants awarded by the Łukasiewicz
Center, grand contract no 2/Ł-IMP/CŁ/2021. The title project: New generation thermally conductive
layers for electronics and the technology of their production.

[1] Materials 2024, 17, 2803.

[2] Tribology International 2024,198, 109905.

[3]Applied Surface Science Advances 2022, 11, 100310.

[4] Surface and Coatings Technology 2019, 359, 141-149.