Abstract: A process for the production of valve seat rings by powder metallurgy wherein molybdenum disulfide in the range of about 0.5% to 1.5% by weight is added to a powder mixture containing 0.8% to 1.5% by weight graphite, 1.0% to 4% by weight lead, 0.5% to 5% by weight nickel, 1.2% to 1.8% by weight molybdenum, 9.6% to 14.4% by weight cobalt, and the remainder iron. The resulting powder mixture is pressed into valve seat rings at a pressing force between 40 and 60 and preferably 50 KN/cm.sup.2. The rings are then sintered in a neutral atmosphere at a temperature of 1100.degree. C. to 1200.degree. C., finally compressed at a pressing force above 120 KN/cm.sup.2 and heat-treated if required. The resulting valve seat rings have greatly improved wear properties when used in internal combustion engines using lead-free gasoline.

Abstract: A composition for compressing and sintering to produce high-wear resistant articles essentially includes between 2% and 10% by weight, preferably 5% by weight, basalt powder and the remainder being metallurgical powder. The metallurgical powder is preferably comprised of austenite steel powder of high commercial quality and the basalt powder is a commercial quality basalt. The article of manufacture is for an internal combustion engine supplied with lead-free fuel wherein the article is comprised of compressed and sintered metal powder having the entire resulting pore space filled with basalt. The article takes the form of a cylinder liner, a valve seat and/or a valve-seat ring.

Abstract: A composition for compressing and sintering to produce high-wear resistant articles essentially includes between 2% and 10% by weight, preferably 5% by weight, basalt powder and the remainder being metallurgical powder. The metallurgical powder is preferably comprised of austenite steel powder of high commercial quality and the basalt powder is a commercial quality basalt. The article of manufacture is for an internal combustion engine supplied with lead-free fuel wherein the article is comprised of compressed and sintered metal powder having the entire resulting pore space filled with basalt. The article takes the form of a cylinder liner, a valve seat and/or a valve-seat ring.