Tribological Behavior of a Cold-Sprayed Cu–MoS2 Composite Coating During Dry Sliding Wear

Cold-sprayed Cu-MoS2 and Cu-MoS2-WC composite coatings were studied for their sliding wear performance in dry nitrogen. Presence of WC particles reduced friction coefficient and improved wear resistance. Dynamics of material transfer, chemical and phase composition of third bodies in the contact were examined. WC particles helped to form transfer films and smooth wear tracks; while rough wear tracks with evidence of detachment were observed for the Cu-MoS2. Subsurface microstructure of the wear tracks showed major microstructural change occurred around WC particles. Microstructure and thickness of the tribolayers at 100 and 1000 cycles exhibited minor changes. However, for Cu-MoS2, microstructural change took place more extensively with sliding, leading to unstable tribolayers, which contributed to crack formation, detachment, and eventually high wear.

show abstract

“…2a and b, respectively. The dark contrast along the particle boundaries is MoS2, as shown in our previous work [16,17]. In Fig.…”

Section: Cold-sprayed Coatingssupporting

confidence: 77%

“…During coating deposition, the gun traverse speed was 60 mm/s. Those spraying parameters were also applied in our previous work for fabrication of Cu-MoS2 composite [16,17].…”

Section: Coating Deposition and Characterizationmentioning

confidence: 99%

Dry sliding wear behaviour of cold-sprayed Cu-MoS2 and Cu-MoS2-WC composite coatings: The influence of WC

Zhang

Epshteyn

Chromik

2018

Tribology International

Self Cite

View full text Add to dashboard Cite

show abstract

“…There have been numerous studies investigating possible tribochemical reactions and the generation of tribo‐layers as well as their influence on friction and wear in both lubricated and dry experiments. [ 5–8 ] Among the various reaction products, oxides are recurrently formed. [ 1,9–12 ] Along with the relative motion, the loading is often associated with a temperature increase in the contact, resulting in oxide formation.…”

Section: Introductionmentioning

confidence: 99%

How Tribo‐Oxidation Alters the Tribological Properties of Copper and Its Oxides

Lehmann

Schwaiger

Rinke

et al. 2020

Adv Materials Inter

View full text Add to dashboard Cite

Tribochemical reactions in many applications determine the performance and lifetime of individual parts or entire engineering systems. The underlying processes are however not yet fully understood. Here, the tribological properties of copper and its oxides are investigated under mild tribological loading and for dry sliding. The oxides represent the late stages of a copper–sapphire tribo‐contact, once the whole copper surface is covered with an oxide. For this purpose, high‐purity copper, thermally‐oxidized and sintered Cu2O and CuO samples are tribologically loaded and eventually formed wear particles analyzed. The tribological behavior of the oxides is found to be beneficial for a reduction of the coefficient of friction (COF), mainly due to an increase in hardness. The results reveal tribochemical reactions when copper oxides are present, irrespective of whether they form during sliding or are existent from the beginning. Most strikingly, a reduction of copper oxide to metallic copper is observed in X‐ray photoelectron spectroscopy measurements. A more accurate understanding of tribo‐oxidation will allow for manufacturing well‐defined surfaces with enhanced tribological properties. This paves the way for extending the lifetime of contacts evincing tribo‐oxidation.

show abstract

“…Furthermore, application of some soft metallic coating can act as solid lubricant [1], which lowers the CoF [3,6,7]. These third bodies formed with metallic coatings [8][9][10][11] are dependent on the chemo-mechanical properties of the coating and the substrate. Sacrificial Cd coating applied on aerospace materials is soft and acts as a lubricant [12], forming third bodies [3] at the contact region making it beneficial for its specific use.…”

Section: Introductionmentioning

confidence: 99%

“…Sacrificial Cd coating applied on aerospace materials is soft and acts as a lubricant [12], forming third bodies [3] at the contact region making it beneficial for its specific use. Though there have been recent work on metallic sliding [8][9][10][11][13][14][15][16], the dynamic nature of the third bodies formed at the interface is difficult to understand and correlate with the change in CoF occurring within one cycle of the test. Available literature for in situ tribometry method [17] used to study the evolution of third body morphology is mostly limited to transfer film and not frequently used to correlate the change in CoF when transfer film is not present.…”

Section: Introductionmentioning

confidence: 99%

Friction transitions and connections to third bodies for a Cd coating on steel substrate

et al. 2020

Self Cite

View full text Add to dashboard Cite

Cd coating is used in aerospace industries from last five decades due to its sacrificial protection and lubrication properties. Although Cd coating is primarily used due to its sacrificial corrosion protection when applied on steel substrate, the added benefit of modifying the tribological behavior by acting as a lubricious layer gives it a leading-edge than other coatings. Often the measurement of friction coefficient (CoF) is reported as a value generated after full sliding cycle. This measurement of average CoF generally limits the study of local variation in CoF occurring within one sliding cycle, which can be significantly different with change in spatial position due to change in third body morphology. In this study, a linearly reciprocating sliding test is used to measure the CoF at a sampling rate of 800 Hz along the track length to generate triboscopic image with steel countersphere. The instantaneous CoF obtained with triboscopy is correlated with the wear track morphology using scanning electron microscope (SEM) and optical profilometer for variation in contact conditions. Tribological test performed in dry atmosphere shows an average CoF of 0.4 till the end of the test whereas with increase in relative humidity to 60%, the average CoF changes from 0.4 to 0.8 at the end of the test due to change in contact conditions. Soft Cd coating on low carbon steel substrate is used to study these variations in third body morphology.

show abstract

Tribological Behavior of a Cold-Sprayed Cu–MoS2 Composite Coating During Dry Sliding Wear

Cited by 50 publications

References 28 publications

Dry sliding wear behaviour of cold-sprayed Cu-MoS2 and Cu-MoS2-WC composite coatings: The influence of WC

Dry sliding wear behaviour of cold-sprayed Cu-MoS2 and Cu-MoS2-WC composite coatings: The influence of WC

How Tribo‐Oxidation Alters the Tribological Properties of Copper and Its Oxides

Friction transitions and connections to third bodies for a Cd coating on steel substrate

Contact Info

Product

Resources

About