Molecular dynamics simulations of ultrathin water film confined between flat diamond plates

Abstract

Molecular dynamics simulations of ultrathin water film confined between atomically flat rigid diamond plates are described. Films with thickness of one and two molecular diameters are concerned and TIP4P model is used for water molecules. Dynamical and equilibrium characteristics of the system for different values of the external load and shear force are investigated. An increase of the external load causes the transition of the film to a solidlike state. This is manifested in a decrease of the diffusion constant and in the ordering of the liquid molecules into quasidiscrete layers. For two-layer film under high loads, the molecules also become ordered parallel to the surfaces. Time dependencies of the friction force and the changes of its average value with the load are obtained. In general, the behaviour of the studied model is consistent with the experimental results obtained for simple liquids with spherical molecules.

The effect of nanolayer thickness on the structure and properties of multilayer TiN/MoN coatings

“…This can be attributed to the two stage pattern of for mation of the phase composition of nanostructured multilayer coatings [9][10][11][13][14][15]. At the onset of growth of Mo 2 N, the determining factor for nucle ation is the atomic sequence of the basic TiN lattice by local epitaxy.…”

“…Therefore, the strength of the nanocomposite increases by pre venting grain boundary shearing (sliding). In terms of the Koehler model [9], valence charge transfer, nan ograin size reduction, and a decrease in the entropy of mixing is a possible mechanism for increasing the hardness of these heterostructures [3,8,[10][11][12][13][14][15]. The lowest wear was observed during deposition of layers with thicknesses of 2 and 10 nm; it was 0.148 and 2.327 × 10 -5 mm 3 N -1 mm -1 for the counterbody and the coating, respectively.…”

Statistical theory of the boundary friction of atomically flat solid surfaces in the presence of a lubricant layer

“…²ÇÊÖÎßÕÂÕÞ ÍÑÏÒßáÕÇÓÐÑÅÑ ÏÑAEÇÎËÓÑÄÂÐËâ ÏÑÎÇÍÖ-ÎâÓÐÑÌ AEËÐÂÏËÍË ÒÑÍÂÊÂÎË, ÚÕÑ ÕÑÐÍÂâ ÏÇÉÒÑÄÇÓØÐÑÔÕ-ÐÂâ ÒÎÈÐÍ ÄÑ ÄÓÇÏâ ÔÍÑÎßÉÇÐËâ ËÔÒÞÕÞÄÂÇÕ ×ÂÊÑÄÞÌ ÒÇÓÇØÑAE ÒÇÓÄÑÅÑ ÓÑAE ÏÇÉAEÖ ÕÄÇÓAEÑÒÑAEÑÃÐÞÏ Ë ÉËAEÍÑ-ÒÑAEÑÃÐÞÏ ÔÑÔÕÑâÐËâÏË [17,18,43], Ë ÒÑÊÄÑÎËÎË ÒÓÇAE-ÒÑÎÑÉËÕß, ÚÕÑ àÕÑÕ ×ÂÊÑÄÞÌ ÒÇÓÇØÑAE âÄÎâÇÕÔâ ÒÓËÚËÐÑÌ ÐÂÃÎáAEÂÇÏÑÅÑ ÒÓÇÓÞÄËÔÕÑÅÑ ÓÇÉËÏ ÒÑÄÇAEÇÐËâ ÒÓÑÔÕÞØ ËÊÑÕÓÑÒÐÞØ ÉËAEÍÑÔÕÇÌ, ÐÂØÑAEâÜËØÔâ ÏÇÉAEÖ AEÄÖÏâ ÕÄÈÓ-AEÞÏË ÍÓËÔÕÂÎÎËÚÇÔÍËÏË ÒÑÄÇÓØÐÑÔÕâÏË. ³ÑÅÎÂÔÐÑ ÕÂ-ÍÑÌ ËÐÕÇÓÒÓÇÕÂÙËË, ÒÓÇÓÞÄËÔÕÞÌ ÓÇÉËÏ ÄÑÊÐËÍÂÇÕ ÔÍÑ-ÓÇÇ Ä ÓÇÊÖÎßÕÂÕÇ ÓÇÊÍËØ ËÊÏÇÐÇÐËÌ ÕÇÍÖÚËØ ÔÄÑÌÔÕÄ ÒÎÈÐÍË ÄÑ ÄÓÇÏâ ÒÇÓÇØÑAE [18,24], ÚÇÏ ÄÔÎÇAEÔÕÄËÇ ÒÑÔÕÇÒÇÐÐÞØ ËÎË ÐÇÒÓÇÓÞÄÐÞØ ËÊÏÇÐÇÐËÌ.…”

Structure and Properties of Multilayer Nanostructured Coatings TiN/MoN Depending on Deposition Conditions

“…Recently, multilayered, multicomponent and nanostructured coatings are the basis of protection products with various functionality, such as increase of hardness, wear, corrosion resistance to high-temperature oxidation, fatigue etc. [13]. TiN [35] and Mo [2,4,6] coatings provide wear protection (when applying them to churlish cutting tools) and in some cases they protect from corrosion.…”