Koppers Company, Inc.

Other

John E Cromwell

Glenn F Hyde

Nicholas Charles Herbert

A coating for piston rings used in internal combustion engines such as diesel engines. The coating is comprised of a physical admixture of primary particles of chromium carbide, nickel chromium and molybdenum. The composition is applied to the piston ring face with a plasma-arc gun and imparts excellent wear resistance to the ring face while lowering cylinder liner wear.

Piston ring coatings

A piston ring having an annular groove in its outer periphery forming axially-spaced outer shoulders at each side of the ring, such groove including a bottom land and a pair of axially-spaced, radially intermediate lands connected to the bottom land and the outer bearing faces by radially outwardly diverging side walls forming stepped sides for the groove with the groove being filled with a layer of electro-deposited chromium. The deposited chromium and the bearing faces form a continuous axially convex surface on the face of the seal ring.

Piston ring with chrome-filled groove

A method of making piston rings comprising forming annular stepped grooves in the outer periphery of a plurality of piston ring blanks, stacking the blanks on a rotatable arbor, electro-depositing a layer of chromium in the grooves and on the outer surfacs of the ring blanks, and removing an outer portion of the chromium layer and the outer bearing faces of the ring blanks to form a plurality of piston rings having a continually axially convex surface on the face of the ring formed by the deposited chromium and bearing faces of the ring.

Method of making piston rings with chrome-filled grooves

A bearing member such as a piston ring for internal combustion engines having a wear resistant alloy coating applied to its wear surface by plasma spraying an aggregate mixture of particles thereon. The mixture is made by first alloying carbon, silicon, chromium, nickel, iron, and boron together to form intermetallic brazing and binding alloy particles and by alloying substantially 75% cobalt and 25% molybdenum to form cobalt-molybdenum alloy particles, for mixing with individual particles of pure molybdenum. These three different particles form the aggregate mixture to be sprayed on the bearing surface.

Bearing member having a wear resistant coating on its bearing face

The invention comprises bearing members having a coated wear surface applied by plasma-spraying an aggregate of particles thereon consisting of nickel-aluminum particles, nickel-molybdenum particles, tungsten carbide particles, and intermetallic alloy particles to form a high temperature, oxidation resistant, wear resistant, and scuff resistant coating. Alloying of the constituents in the final coating is desired and is achieved by encapsulating both the aluminum and molybdenum particles with nickel (alternatively the nickel-aluminum may be in the form of a bonded aggregate), by sintering the tungsten carbide in a matrix of cobalt, and by alloying nickel-cobalt, carbon, silicon, chromium, boron, and iron into an intermetallic alloy to form an aggregate of four types of particles for plasma-spraying onto the wear surface.

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Baltimore, MD, United States of America

John E Cromwell