Abstract: 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.

Abstract: A method of making and the resulting metallurgical product for an apex seal design and/or opposing rubbing surface is disclosed; the seal has ingredients so that it is effective to inherently contain a lubricating film have a retrograde solubility curve so that small additions of chromium can precipitate to achieve a hardening of the matrix, and in some instances an independent graphite lubricant is admixed. A specific example of the composition is a copper-based alloy having 0.1-0.6% chromium and 0.5-1.5% by weight graphite.

Abstract: A method is disclosed for fabricating a rotor housing for a rotary internal combustion engine. A conductive mandrel is prepared having an outer surface complimentary to the resultant rotor housing inner wall, the mandrel is provided with an exterior surface smoothness in the range of 4-12 r.m.s. A functional coating of a composite particle wear-resistant material is electrolytically deposited onto the mandrel (acting as a cathode) to form an assembly, the exposed surface of the assembly is controlled to have a roughness characterized by projections no less than 0.030 inches and concentrated in a number no less than 5/cm.sup.2. The assembly is placed in a die-casting machine where a molten metallic medium is cast thereabout forming a casting which is substantially mechanically locked to the assembly. The mandrel is then stripped from the coating to leave the resultant rotor housing.