Structural and tribological studies of MoS2 solid lubricant films having tailored metal-multilayer nanostructures

Low-friction, high-endurance, ion-beam-deposited PbMoS coatings

“…Ni [4], Au [5]) and even PTFE [6]. More recently, sophisticated deposition techniques such as multilayering of metals in MoS 2 coatings have been developed [7]. Additionally, laser ablation and pulsed laser deposition techniques have been employed to alloy MoS 2 [8,9] and oxides [10,11] with metals.…”

Applications of Surface Science to Solid Lubricants

“…In particular, films incorporating metals to poison edge-plane growth often display higher friction than identical films without the dopant, and the friction appears to scale with the amount of incorporated metal. This effect has been observed in both sliding [93) and rolling tests [98). An understanding of the chemical reactivity of MoS2 with various metals should allow an intelligent selection of metal dopants, namely, an unreactive metal that also possesses some reasonable tribological behavior.…”

“…In both sliding and rolling tests, very dense films, produced by the well-controlled incorporation of dopants or other means to suppress rapid edge-plane growth, generally show the longest wear lives in most tot procedures [93,98]. This doping has been best accomplished by layering films in very clean deposition systems, as discussed earlier.…”

“…Some oxygen substitution in the MoS 2 .x lattice may be advantageous as discussed below, but too much produces poorly ordered films that exhibit inferior wear properties. The adsorption of certain metals, such as Ni or Au, onto edge planes of platelets presents a relatively inert surface that appears to favor basal island growth [85,93]. By alternating thin (5 10 rum) MoS2 layers with very thin (< 1 rim) layers of relatively unreactive metals, a continuously renewed, clean surface for basal island growth is generated.…”

“…(The silicon dioxide surfaces are typical of the type of atmospherically equilibrated surface one obtains with Si 3 N 4 , a promising bearing material with as yet very little practical application.) However, occasionally there have been instances of basal island growth on steel surfaces, which might signify operational possibilities if the proper surface preparation conditions can be devised [92][93][94]. The previous discussion of the reactivities of the metals iron, manganese, and chromium with the basal surface of MoS 2 is pertinent to our understanding of the proper conditions for such ordered growth.…”