A sintered valve guide having a metallic structure that has a matrix composed of a martensite phase dispersed in a pearlite single phase structure or a mixed structure of ferrite and pearlite, and a pore dispersed within the matrix, wherein the martensite phase exists in a proportion such that an area ratio of the martensite phase in a structure cross-section is within a range from 1 to 10% of the matrix is provided. A method for producing a sintered valve guide is provided, the method includes preparing a mixed powder by adding a copper-phosphorous alloy powder, a nickel powder and a graphite powder to an iron powder, molding the mixed powder into a molded body having a density of 6.8 to 7.2 Mg/m.sup.3, and sintering the obtained molded body at a temperature of 950 to 1,200? C.

A method of manufacturing an end piece for a camshaft may include forming a shape of an end piece to be coupled to a camshaft by compacting steel and powder in a net-shape manner and by sintering steel and a powder compact that are preassembled to each other.

An object of this heat-resistant sintered material and a production method therefor is to obtain a heat-resistant sintered material having excellent oxidation resistance, high-temperature wear resistance and salt damage resistance. This heat-resistant sintered material has a composition containing, in mass % values, Cr: 25 to 50%, Ni: 2 to 25% and P: 0.2 to 1.2%, with the remainder being Fe and unavoidable impurities, and has a structure including an FeCr matrix, and a hard phase composed of CrFe alloy particles dispersed within the FeCr matrix, wherein the Cr content of the FeCr matrix is from 24 to 41 mass %, the Cr content of the hard phase is from 30 to 61 mass %, and the effective porosity is 2% or less.

A soft magnetic alloy has a main component of Fe. The soft magnetic alloy contains P. A Fe-rich phase and a Fe-poor phase are contained. An average concentration of P in the Fe-poor phase is 1.5 times or larger than an average concentration of P in the soft magnetic alloy by number of atoms.

An Fe-based amorphous alloy of the present invention has a composition represented by formula (Fe.sub.100-a-b-c-d-eCr.sub.aP.sub.bC.sub.cB.sub.dSi.sub.e (a, b, c, d, and e are in terms of at %), where 0 at %a1.9 at %, 1.7 at %b8.0 at %, 0 at %e1.0 at %, an Fe content (100-a-b-c-d-e) is 77 at % or more, 19 at %b+c+d+e21.1 at %, 0.08b/(b+c+d)0.43, 0.06c/(c+d)0.87, and the Fe-based amorphous alloy has a glass transition temperature (Tg).

The invention concerns pre-alloyed powders useful for the manufacture of metal-bonded diamond tools. A process for the synthesis of such powders is presented, characterized in that at least a major part of the phosphor is introduced by adding an aqueous solution of a phosphorus salt to one or more of the metal-bearing compounds. The powder can have a low cobalt content, or even be cobalt-free, yet remain suitable for the production of diamond-loaded segments having harness and bending characteristics approaching or exceeding that of cobalt.

A metal powder has a formula FeaCubNicCodSnePfMogWhAxOy, wherein, in weight %, a>50, 5<b<25, c<20, d<5, e<5, 0.5<f<5, 0.5<g+h<5, x+y<5, and a+b+c+d+e+f+g+h+x+y=100. A represents one or more elements having a Gibbs free energy of oxidation at 700 C. which is lower than the Gibbs free energy of oxidation of Mo at 700 C. The pre-alloyed powder is useful for the manufacture of metal-bonded diamond tools. The powder can have a low cobalt content, or even be cobalt-free, yet remain suitable for the production of diamond-loaded segments having harness and bending characteristics approaching or exceeding that of cobalt.