Laser modification of the microstructure and mechanical properties of (Cr3C2-25(Ni20Cr))-5(Ni25C) cermet coatings containing a solid lubricant

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

“…Cermet coatings containing ceramic particles embedded in a metallic matrix meet criteria such as anti-wear, high hardness, and compact microstructure with good adhesion [ 1 , 2 , 3 , 4 ]. Protective Cr 3 C 2 -NiCr deposits are manufactured mainly using plasma spraying and HVOF; however, cold spraying is increasingly becoming popular [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. This type of coating has been deposited on various substrates, usually on low-carbon steel [ 5 , 6 , 7 , 8 ], corrosion-resistant steel, and aluminium alloys [ 21 ], depending on the application of the working element.…”

“…The use of ceramics in the coating material allows the properties of the coatings to be improved. The literature data describing cold sprayed cermet Cr 3 C 2 -NiCr coatings show that, depending on the used substrates, they reveal various amounts of Cr 3 C 2 embedded in their structure and mechanical properties [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. For cold sprayed Cr 3 C 2 -25(Ni20Cr), the carbide content built in the deposit was in the range of 22.8–33.8 vol.%, whereas the hardness changed from 449 HV0.3 to 875.7 HV0.2.…”

“…They possess self-lubricating properties and improve the anti-wear properties of substrates. So far, there is limited data on Cr 3 C 2 -25(Ni20Cr) deposits containing graphite as a solid lubricant obtained in the cold spray process [ 18 , 19 ]. Therefore, a detailed examination of these coatings will fill the knowledge gap in this field and show how the used substrates affect the microstructure and properties of these cermet deposits.…”

Nd:YVO4 Laser Irradiation on Cr3C2-25(Ni20Cr) Coating Realized with High Velocity Oxy-Fuel Technology—Analysis of Surface Modification

“…When the number of loop cycles increases, the main effect of laser irradiation on the coated surface is to generate a texture characterized by an average roughness comparable to the initial one, but with higher values of Rz. These latter results could be useful for increasing wear behavior or lubrication ability, as has been demonstrated in other studies [21,27]. • The first experimental series highlighted that the as-sprayed HVOF coatings were characterized by different roughnesses along the x and y directions.…”

“…Some preliminary studies presented in the literature that focus on laser surface modification of carbide coatings are detailed in the following: Morimoto et al tested the effect of a diode laser on a cermet coating, achieving an increase in surface hardness [24]; Sun et al, using a fiber laser, tested the effect of scan speed on wear behavior and observed that the wear resistance of the optimized layer was increased by 29.76 times [25]. Scendo et al investigated the influence of the CO 2 laser remelting process, and found that the micro-hardness of a cermet coating decreased as the speed of laser irradiation increased [26]; Goral et al, presented a study considering the effect of laser surface treatment on microstructure and mechanical characteristics, highlighting that cermet coatings were characterized by compressive residual stresses whose value increased with higher laser power [27]. The main contribution of this research with respect to the cited literature is that we analyze the effect of process parameters, including the laser scanning rate, scanning strategy, and loop cycle of an untested laser source (Nd:YVO 4 ), in order to measure the effect of laser surface modification and, thus, analyze the potential of this laser source to treat cermet carbide.…”