Wear resistant coating and process of its manufacture

摘要

#CMT# #/CMT# A wear-resistant coating (A), for predetermined surfaces of a machine part exposed to frictional wear, comprises at least one metal-free amorphous hydrocarbon layer (I) containing sp 2>- and sp 3>hybridized carbon. #CMT# : #/CMT# An independent claim is included for the production of (A), by applying the layer (I) to the machine part surface to reduce friction and increase the wear resistance of the surface. #CMT#USE : #/CMT# (A) is specifically used for wear-resistant coating (and optionally also electrical insulation) of machine parts of steel (especially the steels 16 Mn Cr 5, C 45, 100 Cr 6, 31 Cr Mo V 9, 80 Cr 2), especially where the surface to be coated is a lifting disk of a central plate of a pump in a fuel supply unit, the central plate of a fuel supply unit, a valve operating component (e.g. a cup tappet, camshaft, hydraulic support or insertion element), roller bearing component, control piston, release valve, piston bolt, mounting bush, univeral joint bush, linear guide or mechatronic system element (all claimed). In particular a roller bearing with a coating (A) on the inner ring, outer ring and/or roller body is independently claimed. #CMT#ADVANTAGE : #/CMT# The thin coating (A) adheres firmly to the substrate and provides the machine part with a permanently reduced coefficient of friction (lasting for the whole of its operating life), without adversely affecting operating tolerances. Being free of metal, (A) also provides electrical insulation. Coating with (A) allows roller bearings to be produced from inexpensive low alloyed steels. #CMT#METALLURGY : #/CMT# Preferred Coatings: (I) optionally contains a non-metallic element component (specifically silicon or oxygen), preferably at less than 30 atomic %. (I) has a hydrogen content of at most 20 atomic %, contains less than 1 atomic % of impurities introduced during processing and has a thickness of 1-70 (preferably 1-10) mu m. At least one adhesion promoting layer (II), at least one intermediate layer (III) and/or an oxide or nitride ceramic layer (IV) is optionally provided between (I) and the machine part surface. (II) is specifically at least partially of metallic material, boride, carbide, oxide and/or nitride of transition metals or of chromium and steel; and is preferably 0.1-0.5 mu m thick. (III) is specifically of hydrocarbon containing a metal (especially tungsten, chromium, titanium, hafnium and/or germanium); and is preferably 0.5-2.0 mu m thick. (IV) is specifically of aluminum oxide, titanium dioxide, aluminum nitride or titanium nitride. Preferred Process: The layer (I) is applied by a physical vapor deposition (PVD) process and/or a (plasma assisted) chemical vapor deposition ((PA)CVD) process. The machine part surface is cleaned before deposition of (I), specifically by cleaning in various baths followed by degassing in a furnace. #CMT#EXAMPLE : #/CMT# No relevant example given.