Influence of WC on third body behaviour during fretting of cold-sprayed Cu MoS2WC composites

Abstract

Fretting wear behaviour of cold-sprayed Cu-MoS2 and Cu-MoS2-WC composites rubbing against AISI 440C steel was studied under gross slip regime. Third body rheology during running-in and steady state was expressed using tribological circuit according to morphology observations on wear scars and transfer materials on the counterfaces. The velocity accommodation mechanisms (VAMs) were therefore identified. Presence of WC particles boosted generation and ejection of large wear particles during running-in and early steady state, yet promoted more stable and lower third body formation and ejection flows over the subsequent test, which led to considerably improved wear resistance. During steady state, the 12 wt.% of WC particles were able to prevent rapid detachment of tribologically transformed structure (TTS) layer and transfer film that was induced by MoS2. This was believed to be attributed from microwedging and pinning of the WC fragments.

Copper-Based Composite Coatings by Solid-State Cold Spray Deposition: A Review

“…Subsequently, research on the influence of WC particles on the third bodies and wear resistance was conducted by changing the concentrations of Cu-MoS 2 and WC powders in the experiments, which yielded similar results. The presence of WC particles contributes to the formation of a continuous tribological transition structure (TTS) layer and a transfer film during the contact process, which makes the third-body flow smaller and more stable, so as to significantly improve the wear resistance of the Cu-MoS 2 -WC coating [55].…”

“…Subsequently, research on the influence of WC particles on the third bodies and wear resistance was conducted by changing the concentrations of Cu-MoS2 and WC powders in the experiments, which yielded similar results. The presence of WC particles contributes to the formation of a continuous tribological transition structure (TTS) layer and a transfer film during the contact process, which makes the third-body flow smaller and more stable, so as to significantly improve the wear resistance of the Cu-MoS2-WC coating [55]. In the preparation of Ni-hexagonal boron nitride (hBN) self-lubricating coatings by mechanical grinding and CS, Smid et al [100] found that the self-lubricating and wear resistance of the coating achieved the optimal performance when the maximum amount of hBN in the cold-sprayed Ni coating is about 6 wt%.…”

Cold Sprayed Tungsten Armor for Tokamak First Wall

“…Even then, the studies employing such concept are limited in the literature and involve successful depositions of W-Cu by Kang and Kang [10] and Deng et al [11], W-Ni-Fe by Xia et al [12], and low tungsten content in W-90Ta coatings by Barnett et al [13] only. Considering their excellent wear properties, a significantly broader series of studies involved the research of cemented carbides in a form of WC-Co [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], WC-Ni [32][33][34][35][36][37][38][39][40][41], WC-Co-Ni [42], WC-Co-Cr [31,[43][44][45], or WC-Cu-MoS 2 [46,47]. Unfortunately, the carbides could not be used for PFCs and so we could not built on these results.…”