Abstract: A slide contacting member which is subjected to slide contact with a counter member. The slide contacting member is made by applying a hard layer, e.g., chromium, onto a parent material, irradiating the hard layer with a high energy density laser beam onto the plating under conditions such that concavities having a softened layer are formed thereon, the concavities being used to keep oil during the contact with the other member. The hard layer is finished grinded after irradiation.

Abstract: A rotor housing for a rotary piston engine having improved gas sealing property between the inner surface and apex seals mounted on a rotor. The rotor housing has an inner surface applied with a hard layer such as chrome plating. The portions of the hard layer surrounding openings of plug holes at the inner surface side are formed with softened areas having lower hardness than the apex seals. The softened areas can be made by a high-energy beam such as a laser beam. Should portions surrounding the openings of the plug holes be thermally deformed to project inward and scratch the apex seals, the projected portions formed of the softened areas will be worn before the apex seals. Hence, uneven wearing of the apex seals can be avoided, which prevents degradation of the gas sealing property and consequently prevents drop in the compression pressure in the working chambers.

Abstract: There is disclosed a rotor housing for a rotary piston engine which is designed particularly for high output power wherein the rotor housing inner wall surface is required to possess heat and wear resistant properties, improved affinity to lubricant oil, resistance to uneven wear which may cause chatter marks and scratches, oil retaining property, and less harmfulness to the apex seal. The rotor housing is formed at the inner wall surface with a porous Cr-Mo plating containing 0.50 to 0.90% in weight of Mo.

Abstract: A process for manufacturing a member having a wear resistant sliding surface. The process includes the steps of providing a metallic substrate having a surface covered by a photo-resist coating, forming the photo-resist coating with a pattern of hard and soft portions, removing the photo-resist coating at the soft portions to expose surface portions of the metallic substrate beneath the soft portions of the photo-resist coating, etching the metallic substrate with the hard portion of the photo-resist coating retained thereon to form pits in the surface portions of the metallic substrate, spraying molten filler material on the surface of the metallic substrate with the hard portion of the photo-resist coating thereon, to fill the pits with the filler material of a porous structure having an oil-retaining capability, and removing the hard portion of the photo-resist coating from the metallic substrate.

Abstract: A sliding member having a number of oil retaining pores is manufactured by forming a hard plating layer on a metal base, forming a masking resist film on the hard plating layer by exposure to light and development, forming a number of pores in the hard plating layer by effecting electrolytic etching at a current density of 50 to 600 A/dm.sup.2, dissolving said masking resist film and removing the same, and forming a hard ceramic film on the hard plating layer by vapor phase plating.

Abstract: A nitrided cast iron product comprising cast iron matrix material and graphite particles distributed in the matrix material, a nitrided layer formed in a surface of the cast iron product and having gaps between the graphite particles and the matrix material, the gaps being exposed to the surface of the product and filled with resin which has a resistance to dissolution under a temperature below 250.degree. C.