Federal-Mogul Burscheid Gmbh

Christian Herbst-Dederichs

Peter-Klaus Esser

Manfred Fischer

Ralf Lammers

Sebastian Bresinski

Stefan Duerdoth

Stefan Dürdoth

Waldemar Urbatzka

A coated piston ring having a base body of chromium steel with more than 10 wt.-% chromium and having an inner circumferential surface, a first flank surface, a second flank surface and an outer circumferential surface. The first flank surface comprises a nitride diffusion layer with a layer thickness of from 5-300 &#x3bc;m, a nitride connecting layer with a layer thickness of from 0.5-15 &#x3bc;m on the nitride diffusion layer, and an oxide layer with a layer thickness of from 0.05-3 &#x3bc;m on the nitride connecting layer. The second flank surface comprises the nitride diffusion layer, and the outer circumferential surface comprises the nitride diffusion layer and a chromium solid particle layer with 0.1-30 vol.-% solid particles, relative to the total volume of the chromium solid particle layer on the nitride diffusion layer.

Piston ring with chromium solid particle wear-prevention layer and corrosion-resistant flank surface

A piston ring, in particular a compression piston ring, includes a running surface, upper and lower flank areas, an inner peripheral area and a joint. The wall thickness of the piston ring is uniform over its periphery and at least the running surface is provided with a PVD coating or a CVD layer in such a manner that the running surface layer has a lesser layer thickness in the peripheral area close to the joint than in the remaining peripheral area of the running surface.

Piston ring

A piston ring includes a running surface having a running surface profile, and an upper flank surface and a lower flank surface. At least the running surface is provided with a vapor-deposited layer such that part of the running surface is provided with a removable cover enabling an essentially sharp-edged running edge to be formed between the running surface and at least one of the flank surfaces, once the vapor-deposited layer has been produced and the cover has been removed.

Piston ring and method for the production thereof

The invention relates to a wear protection layer for piston rings in internal combustion engines consisting essentially of chromium carbides, wolfram carbide, chromium and nickel. The wear protection layer is formed from a mixture of powders in which the first powder consists of at least the alloy components chromium carbide, chromium and nickel, in the form of an agglomerated and sintered powder, and which has not been subjected to any secondary heat treatment that would make the powder brittle, such as plasma refinement, the carbides in the powder having an average diameter of essentially not more than 3 &#x3bc;m. A second powder, also in the form of an agglomerated and sintered powder, contains wolfram carbide and is applied to at least one peripheral surface of the piston rings by thermal injection, so that two distinctive coating areas are produced in the wear protection layer. A first area, predominantly rich in chromium, and a second area, mainly rich in wolfram carbide are formed.

Wear protection layer for piston rings, containing wolfram carbide and chromium carbide

The invention relates to a wear-resistant coating used for bearing surfaces and flanks of piston rings in internal combustion engines. The wear-resistant inventive coating is obtained by mechanically alloying powders which form a metallic matrix with hard material dispersoids and lubricant material dispersoids. The coating is then thermally applied to the workpieces, especially by means of high velocity oxygen fuel spraying (HVOF). The workpieces coated are bearing surfaces and parts of flanks pertaining to piston rings in internal combustion engines.

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Burscheid, Germany

Christian Herbst-Dederichs