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 article describes the influence of a solid lubricant such as graphite on the coating-substrate adhesion, susceptibility to cracking during three-point bending tests and tribological properties of the cermet coating-substrate systems. Two types of deposits Cr₃C₂-25(Ni20Cr) and (Cr₃C₂-25(Ni20Cr))-5(Ni25C), cold-sprayed on the Al 7075 alloy substrate, were analyzed. The Cr₃C₂-25(Ni20Cr) coatings showed a homogeneous microstructure with evenly distributed ceramic particles in a Ni20Cr matrix. The (Cr₃C₂-25(Ni20Cr))-5(Ni25C) deposits also contained graphite placed both between metallic particles and near the crushed ceramic Cr₃C₂ particles. The force required for the crack that appeared in the coating-substrate system during the three-point bending test under constant velocity was significantly higher in the case of (Cr₃C₂-25(Ni20Cr))-5(Ni25C) deposit than in that without the solid lubricant. The cracks were observed perpendicular to the coating-substrate interface. The graphite embedded in the cermet coating structure prevented the formation of crack nuclei during three-point bending test under cyclic load at room temperature and reduced the size of cracks in the deposit at 200 °C. Both cermet coatings revealed the same adhesion. The addition of graphite not only did not deteriorate the adhesion of the deposits and thus their quality but also improved their other properties, such as flexural strength and wear resistance. Coatings containing the solid lubricant showed a lower wear index than the Cr₃C₂-25(Ni20Cr) deposits examined at both room and elevated temperatures. This recommends their use in industry as deposit working in heavy wear conditions. The presented results of mechanical tests effectively fill the gap regarding the properties of the cold-sprayed cermet coatings.

Cold-sprayed composite coatings have several advantages; however, some properties, such as hardness and abrasion resistance, are lower than those in plasma- or HVOF-sprayed deposits. This work showed that the use of surface diode laser processing allowed the development of (Cr₃C₂-25(Ni20Cr))-(Ni-graphite) cermet coatings with good adhesion to the steel substrate, and increased properties in the near-surface zone, below which the properties of cold-sprayed coatings were retained. Studies of the microstructure in the micro/nanoscale of the laser-treated coatings showed strong grain refinement after surface treatment. Cr₇C₃ carbide of various shapes and sizes was formed in the structure; while, a several hundred nanometre layer of Cr₂O₃ oxide appeared on the coating surface. The changes occurring in the microstructure have resulted in increased mechanical and tribological properties of the laser-treated zone of deposits.

This study analyzed the mechanical properties of cold-sprayed Cr₃C₂-25(Ni20Cr) blended with Ni-graphite as a solid lubricant deposited on 7075 aluminum alloy substrate. To optimize the coating properties, different sets of parameters (graphite content in feedstock, process gas composition, spraying distance, and traverse gun speed) were tested in the frame of the Taguchi experiment. The cold-sprayed coatings were evaluated for their chromium carbide and graphite content, hardness, and coefficient of friction. Analysis of the microstructure of the deposited coatings revealed that graphite as a soft and brittle component fills all voids in the coating and its quantity depends on its content in the feedstock. The experimental results show that the composition of the process gas has the greatest impact on the Cr₃C₂ content in the coating and the proportion of graphite in the sprayed blend directly affects its hardness. In the case of the coefficient of friction, the most significant parameters were the graphite content in the sprayed blend, the spraying distance, and process gas composition. The conducted verification experiment with the optimum parameter values allowed a coating with the highest hardness and the lowest coefficient of friction to be obtained.

Iron-based metallic glasses are gaining increased interest due to their good glass-forming ability, high compressive strength, high corrosion resistance, catalytic properties, excellent soft magnetic properties, and relatively low cost. Cold spraying was successfully used to produce amorphous coatings from commercially available powder without any crystallization due to its high cooling rate and short processing time, minimizing thermal influences. Thick and dense amorphous coatings were obtained. The effect of a substrate on the microstructure, phase composition, microhardness, flexural strength, and wear behaviour of the coatings was investigated. The cold sprayed coatings revealed an almost complete amorphous structure and negligible porosity. The coating deposited on the steel substrate showed higher microhardness, better resistance to loose abrasive wear, and a slightly lower wear index tested in the coating and Si₃N₄ ball tribological association than that cold sprayed on an Al alloy. The force required to destroy the durability of the coating–steel substrate system estimated during three-point bending tests was also much higher. Both coatings were characterized by a comparable friction coefficient.