Tribology of Co-sputtered Nanocomposite Au/MoS₂Solid Lubricant Films over a Wide Contact Stress Range

Abstract

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of Information. SPONSOR/MONITOR'S ACRONYM(S) SMC SPONSOR/MONITOR'S REPORT NUMBER(S)SMC-TR-05-12 DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution unlimited. SUPPLEMENTARY NOTES ABSTRACTSlip-ring assemblies for spacecraft, and other sliding electrical contacts, require low friction and wear, as well as low electrical resistance and noise. Most current slip-ring technologies (both solid-and liquid-lubricated) are over forty years old, and their robustness is often less than satisfactory. Newer technologies have been developed, but have also shown limitations in spacecraft applications. We are investigating alternate material technologies to address these issues, concentrating on sputter-deposition of metals (e.g., gold) containing solid lubricants (e.g., MoS 2 ) to form electrically conductive, lubricious nanocomposite films. In the present study, we investigated the friction and endurance of co-sputtered Au/MoS 2 films in sliding contact in N 2 gas at different contact stresses. Seven different film compositions were studied. Films with higher metal contents were found to perform especially well at low contact stresses, which is the regime where sliding electrical contacts operate (i.e., <1 MPa). Auger Nanoprobe analysis was used to reveal how low friction is produced, even at contact stresses well below that usually used in MoS 2 -lubricated systems. SUBJECT TERMS

Complex frictional analysis of self-lubricant W-S-C/Cr coating

“…There are several reports dealing with thin films based on TMD alloyed with metals, such as (Ti [6,7,27], Al [28], Au [29,30], Pb [31], Ni [32,33], Cr [34,35]); the effects of doping metal on the coating structure, density, or mechanical properties are well studied. However, the role of doping metal in the tribological contact remains reactions of the metals with residual atmosphere in the deposition chamber, particularly with oxygen.…”

Aspekty nanomateriałów w zastosowaniach cywilnych i militarnych. Część 2. Wykorzystanie i obawy wynikające z ich uwalniania do środowiska przyrodniczego

“…kwiatopochodna struktura TiO2 [12,19,39,[40][41][42][43]188]; j) materiałów polimerowych z wbudowanymi nanocząstkami inżynierskim (np. Au/MoS2), dzięki którym nabierają one wysoką odporność na ścieranie oraz właściwości ślizgowe, co sprawia, że znajdują one zastosowanie, jako bezsmarowe elementy maszyn [12,19,40,182,[200][201][202][203][204][205][206][207][208][209][210]; k) materiałów odpornych na oddziaływanie wysokiej temperatury m.in. materiałów ceramicznych [10,12,16,19,32,84,[208][209][210]; l) nanokrystalicznych materiałów stosowanych jako materiały gradientowe FGM's (ang.…”

Synthesis of MoS2-Au nanocomposite films by sputter deposition.

“…Transition metal dichalcogenides, most notably molybdenum disulfide (MoS 2 ) and tungsten disulfide (WS 2 ), are well known for their solid lubricating behavior [1][2][3][4][5][6][7][8][9][10]. In the MoS 2 layered structure, a sheet of molybdenum atoms is sandwiched between two hexagonally packed sulfur layers as shown in Figure 1-1.…”

“…A number of metal or oxide dopants in MoS 2 have also been successfully tried. Notable examples of dopants include: Ti [17][18][19][20][21], Al [22,23], Ni [24][25][26], Au [8,24,26], Pb [24,27,28], PbO [24,29,30], Sb 2 O 3 [25,[30][31][32][33][34][35]. The presence of these dopants can lead to increased coating density, hardness, and oxidation resistance.…”