The Effect of the Substrate on the Microstructure and Tribological Properties of Cold Sprayed (Cr3C2-25(Ni20Cr))-(Ni-graphite) Cermet Coatings

Abstract

In this work, the effect of the substrate, Al 7075 alloy and 1H18NT9 stainless steel, on the microstructure and tribological properties of cold sprayed (Cr3C2-25(Ni20Cr))-(Ni-graphite) coatings was investigated. Both coatings were dense and did not reveal any discontinuities at the interfaces. They had similar Cr3C2 and graphite contents. Their microstructures showed a variety of grain sizes of the matrix phase between the inner part of the splat, showing large ones, and their boundaries, where elongated and nanostructured grains were formed during the deposition process. The coating deposited on the steel substrate revealed a slightly higher hardness and lower abrasive wear with the Al2O3 loose abrasive particles. The force required to destroy the durability of the coating–steel substrate system in the three-point bending test was higher than those of the other ones. The cermet deposit cold sprayed on steel and examined at 25 °C under 10 N revealed the best wear resistance and the lowest friction coefficient.

The Microstructure, Surface Topography and Wear Resistance of Cold-Sprayed (Cr3C2-25(Ni20Cr))-(Ni-graphite) Composite Coatings Modified by Diode Laser Treatment

“…3). The coatings showed no changes in phase composition compared to the feedstock powders, as tested in previous studies (Ref 7,12). The laser-treated deposits showed new phases, such as Cr…”

“…From the application perspective, it is important that coatings can be characterised by high hardness, wear resistance, low friction coefficient and a compact structure in the usable zone, while maintaining high adhesion. These expectations can be met by cold-sprayed cermet coatings and subjected to laser surface treatment because, in the modified zone, they have good mechanical and tribological properties, whereas below they are characterised by a compact structure without pores and good adhesion with the substrate, which results from the metallurgical bond that is formed by adiabatic shear instability and mechanical interlocking mechanisms ( Ref 7,18).…”

Study on the new solution of air plasma spray for improving the performance of amorphous coatings

“…A hard ceramic phase normally constitutes up to 80% by volume, a remaining is a metal-binding phase [9]. For the continuous improvement of the performance of cermet materials, recent publications are valuable contribution related not only to theoretical but also experimental studies encouraging the progressive technologies, innovative development, and manufacturing processes, that promote their potential role for the industry [10,11,12,13]. The newly developed group of wear-resistant materials is amorphous with sophisticated performance.…”