Ford Motor Company Limited

James C Uy

Andre Ezis

David Moskowitz

Yeshwant P Telang

A method of making a silicon nitride part is disclosed. In this method an article of silicon nitride is first made which has a density less than the theoretical density of silicon nitride. This article also contains a densification aid. The entire surface area of this article is coated with a thin silicon nitride skin which is gas impervious. The so coated article is heated to a temperature for a time sufficient so that some of the densification aid may diffuse into the silicon nitride skin. The so treated article is then subjected to a pressure sufficiently high, for a time sufficiently long and at a temperature which permits the silicon nitride article and skin thereon to be compacted to increase the density of the article to a density greater than it originally had and to form the silicon nitride skin about the article so that the skin becomes an integral of the finished part.

Method of making a silicon nitride part

An apex seal element for a rotary internal combustion engine is described which is comprised of a cemented carbide having a binder constituted of nickel and molybdenum carbide and a controlled addition of excess free carbon (or equivalent lubricating agent).

Apex seal composition for rotary engines

A rotor housing for a rotary internal combustion engine is disclosed having a wear-resistant coating system characterized by high temperature hardness stability and controlled porosity to improve the lubricating characteristics of the surface-to-surface engagement with the rotary apex seals. The coating system comprises a self-fused composite of martensitic stainless steel powder and an equally hard powder consisting of a nickel-based alloy. Powder particle size is controlled to render a smoother machined surface and sub-surface porosity. An intermediate transition coating may be used consisting of a composition selected from nickel aluminide, are sprayed nickel, molybdenum, all effective to operate as a bonding intermediate to a supporting aluminum structure. A method of producing the wear-resistant coating system for a rotor housing is disclosed, comprising preparation of an aluminum casting having a supporting epitrochoid end wall, machining a reference, embedment of thermally resistant plugs about certain openings in the end wall, removing a uniform layer of said casting end wall to a predetermined depth, soft grit blasting of the removed surface, coating of the margins about ports in the end wall with an anti-bond material flame spraying the entire end wall with a mixture of martensitic stainless steel and a nickel-based alloy, immersing said coated casting in oil for a predetermined period of time immediately after coating, and grinding off a portion of said coating to the depth of said reference.

Coating for rotary engine rotor housings and method of making

A rotary internal combustion engine and particularly an improved rotor construction for such engine and method of making is disclosed. A coating system is applied at least to the flank surfaces of the rotor which face the variable volume combustion chambers of the engine, the system serving to reduce heat flow to the oil lubrication system within the rotor and to quench heat build-up on the above surfaces to prevent pre-ignition. The engine is permitted to run at a somewhat higher operating temperature resulting in increased efficiency, better fuel consumption and reduction of emissions. In the method of construction, vaporizing means is employed to supply vaporizable material from two crucibles. The means can be controlled to deposit one or a mixture of said vaporizable materials. One crucible contains an adherent conductive metal and the other crucible contains an insulating medium. The vaporizing means is controlled to deposit a first layer consisting of the adherent conductive metal, a second layer consisting of a mixture of the insulating medium and adherent conductive metal, a third layer consisting essentially of an insulating medium, a fourth layer consisting essentially of a mixture of the adherent metal and insulating medium, and a fifth layer consisting of solely the adherent conductive metal.

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Dearborn Heights, MI, United States of America

James C Uy