Abstract: In a method for producing by a powder-metallurgical method a wear-resistant iron-based sintered alloy, which essentially consists of from 0.3 to 2.5% by weight of C, from 1 to 8% of Cu, from 3 to 14% of at least one element selected from the group consisting of Cr, Mo, W, V, Nb, and Ta, and Fe and the unavoidable impurities in balance, and which has a micro-structure such that a majority of the alloying elements are uniformly dissolved as solutes of the iron matrix and fine Cu phase is uniformly dispersed, a composite powder which consists of iron or iron alloy and Cu which is present mainly on the surface of the composite powder is used in the raw-material powder.

Abstract: A material for valve seats comprising a wear resisting sintered ferro alloy formed by dispersing particles of a high speed steel in a matrix in which hard alloy particles are dispersed. Steps for forming include mixing particles of a matrix material, carbide material and a hard alloy, and blending the mixture with high speed steel particles, pressurizing and compacting the mixture after blending, then sintering them at 1000.degree. to 1200.degree. C. In the preferred method, at least one element of Fe, C, Ni, Co, Si or Mn is included as the matrix material, and at least one element of Fe, Cr, Mo or V as the carbide material and at least one element of Fe, Cr, Mo, Co, C or W as the hard alloy are prepared. Furthermore, the ferro alloy preferably includes the following amounts of the above mentioned elements, 0.5 to 2.0 wt % of C, 1 to 25 wt % of one or more of Cr, Mo, V, or W and 1 to 15 wt % of one or more of Co, Ni, Mn, or Si.

Abstract: An iron-base sintered alloy especially suitable for valve seat manufacture having excellent wear resistance and being able to be machine-cut is provided. The alloy is produced by combining specifically atomized pre-alloyed powder, iron powder, nickel powder and graphite powder by means of compacting and sintering processes, and has a microstructure comprising pearlite and globular hard alloy phase formed with said atomized pre-alloyed hard alloy powder uniformly dispersed in said pearlite and martensite surrounding said hard alloy phase.

Abstract: A novel group of iron-base sintered alloys especially suitable for valve seat manufacture having excellent wear resistance and good machinability is provided. The alloy is produced by a combination of specific atomized pre-alloyed powder, iron powder and graphite powder by compacting and sintering processes. Various manufacturing methods with or without infiltration of filler materials into pores in the sintered product to improve wear resistance and machinability are disclosed.