The invention relates to a method for manufacturing an epilame mechanical part (2) comprising a substrate (4) made of a first material, the method comprising at least: a step (10) of depositing an epilame product (6) consisting of a second material on the substrate (4), said deposition being carried out in the form of a projection onto the substrate (4) of at least one collimated or localised beam (12; 12A, 12B) of material containing the epilame product (6); and a step (11) of treating the second material to ensure the cohesion of the components on the substrate (4).

A self-lubricating solid composite coating configured for an application to timepiece mechanisms, including particles of graphene and/or graphene oxide distributed in a metal matrix.

A low friction assembly is desired. The present invention relates to a new low-friction lubrication assembly comprising a first member relatively slidable against a second member, the first member having chemical affinity with an OH-group on its sliding surface; and one or more oxygen containing compounds, provided on the sliding surface of the first member and being able to produce a tribofilm attached to the sliding surface of the first member through hydrogen bond interactions. Preferably the second member comprises a similar OH-terminated sliding surface wherein an oxygen containing compound (lubricant)-supported interface between the first and second sliding surfaces results in a H- and/or OH-terminated interface developing repulsive forces thereinbetween.

A timepiece component comprising a dry, self-lubricating surface layer, consisting entirely of boric acid, having a thickness of 50 nanometres to 1 micrometre. A method for coating a timepiece component with a self-lubricating surface layer, including dissolving, at ambient temperature, boric acid H.sub.3BO.sub.3 granules or powder in a solvent chosen from among water, isopropanol, propanol, methanol, methyl propanol, glycol ethylene, glycerol, acetone, in a proportion of 0.01% to 1.0% by mass; mixing and agitating the solution; dipping the component to be coated in this solution; removing the component from the solution and allowing the liquid phase to evaporate, with the surface forming the surface layer kept away from any foreign bodies, until evaporation is complete; and repeating the dipping and evaporation steps until the desired layer thickness is obtained, from 10 nanometres to 1 micrometer, or more particularly from 50 nanometres to 1 micrometre.

A timepiece escapement mechanism with improved tribology includes at least one pair of components including a first component and a second component respectively including a first friction surface and a second friction surface which are arranged to cooperate in contact with each other. The second friction surface includes at least one silicon-based material taken from a group including silicon, silicon dioxide, amorphous silicon, polycrystalline silicon, porous silicon, or a mixture of silicon and silicon oxide. The first friction surface is formed by a surface of a solid element which is made of solid silicon nitride in a stoichiometric formulation Si.sub.3N.sub.4. A method for making the escapement mechanism is also provided.