A Study of Wear in Thin Coatings Applied to Convex-Concave Gearings

Abstract

The submitted contribution deals with the wear of thin coatings applied to convex–concave gearings for gear made from C45E steel. The influence of the tribological characteristics (friction coefficient, wear, adhesion and hardness) of the TiN, TiCN coatings and the combined coating of TiCN + MoS2 on convex–concave gearing is described, from the aspects of scuffing formation. Scuffing tests were done on C–C gears. Coatings were applied by arc–ion-plating (AIP) and magnetron sputter-ion-plating (MSIP) methods. The thickness of the deposited coating and its chemical composition were determined by SEM and EDX analysis. Load-bearing capacity was evaluated by a Niemann tester. The TiCN + MoS2 combined coating with the MoS2 layer on the top reached the lowest coefficient of friction. However, after a rapid wearing of the MoS2 layer, this value dropped to a comparable value of TiCN. The nano-hardness of the TiCN layer was higher in comparison with TiN. Thin and soft MoS2 layers cracked already at lower load levels and separated from the substrate at the 5th load stage. The formation of scuffings for selected coatings documented in this article was solved for convex–concave gearing working also in interaction with Biogear S 150 and Biohyd MS 46 oils.

Wear of AlCrN and CrAlSiN Coatings Applied to Nonstandard Involute Gears

“…Based on the results of previous experiments [15][16][17], the contact pressures on the gear tooth surface (tooth face, tooth pitch, and tooth flank) were calculated at the 10th, 11th, and 12th load stages during the Niemann test of HCR gears (Table 1). Based on the results of previous experiments [15][16][17], the contact pressures on the gear tooth surface (tooth face, tooth pitch, and tooth flank) were calculated at the 10th, 11th, and 12th load stages during the Niemann test of HCR gears (Table 1). From Table 1, it is evident that the highest contact pressures were calculated on the tooth flank and the lowest contact pressures on the tooth face.…”

“…Therefore, in the next experiments it will be necessary to modify deposition Wear of gear tooth with CrAlSiN coating showed similar characteristics on tooth face, pitch, and flank as wear in the case of AlCrN coating and therefore it was not documented in detail. Literary sources [16][17][18][19] presume longer lifetime of CrAlSiN coatings than AlCrN coatings. Values of hardness, wear resistance and friction coefficient should confirm these presumptions.…”

“…The progress in surface engineering has enabled applications of several deposition methods such as PVD, CVD, and PACVD, with the aim of increasing surface bearing capacity of gear teeth [14,15]. Deposition of hard thin coatings on the gear tooth surface is one way of increasing the surface bearing capacity of the teeth, which enables one to increase the load capacity of gears while maintaining their required lifetime [16,17].…”

Comparative Analysis of Simulation Results of Hard-to-Cut Materials Machining by Coated Cutting Tools

“…A generalized analysis of literary sources [4,6,9,10,12,13,14,15] concerning of the cutting process simulation using a wear-resistant coating tool makes it possible to draw the following conclusions:…”