Abstract: The invention relates to a sintered alloy. This sintered alloy includes 3-13.4 wt % of W, 0.4-5.6 wt % or 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. The sintered alloy includes first and second phase which are distributed therein, in a form of spots, respectively. The second phase is in an amount of from 20 to 80 wt %, based on the total weight of the first and second phases. The first phase contains 3-7 wt % of W, 0.5-1.5 wt % of optional V, up to 1 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. The second phase contains 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. When the manganese contents of the first and second phases and the total of the sintered alloy are respectively in a range of from 0.2 to 1.

Abstract: An iron base sintered alloy with dispersed hard particles is provided which comprises by weight 3 to 15% nickel (Ni), 0.5 to 5% chromium (Cr), 0.5 to 2.0% carbon (C), the remainder iron (Fe) and unavoidable impurities. At least a part of nickel (Ni), molybdenum (Mo) and chromium (Cr) is contained in solid solution of an iron base matrix. At least a part of molybdenum (Mo) and chromium (Cr) is dispersed within the iron base matrix to form fine carbides or intermetallic compounds thereof. Uniformly dispersed within the iron base matrix are hard particles of 3 to 20% contain 50 to 57% chromium (Cr), 18 to 22% molybdenum (Mo), 8 to 12% cobalt (Co), 0.1 to 1.4% carbon (C), 0.8 to 1.3% silicon (Si) and the remainder iron (Fe) to strengthen the dispersion and remarkably improve wear resistance.

Abstract: A method of manufacturing a connecting rod is disclosed, in which a formed body of a connecting rod integrated with a cap section of iron metal powder is heated, before or after being sintered, with a bearing metal ring set in the bearing section thereof. During or after sintering, the bearing metal is infiltrated in the bearing section, followed by the forging as required. Then the cap section is separated. In this way, the manufacturing steps are reduced, while at the same time preventing the bearing section from being overheated and seizured due to an improved heat conductivity between the connecting rod body and the bearing section.

Abstract: The invention relates to a method of preparing a composite sintered body having inner and outer portions fitted with each other. The method includes the steps of: (a) preparing an inner powder compact; (b) preparing an outer powder compact; (c) fitting the inner and outer powder compacts with each other so as to prepare a composite powder compact; and (d) sintering the composite powder compact so as to prepare the composite sintered body. The inner and outer powder compacts are respectively selected such that, during the step (d), the amount of growth of the inner powder compact becomes greater than that of the outer powder compact. Each of the inner and outer composite powder compacts is made of one member selected from the group consisting of a wax-type segregation prevention powder mixture and a metal-soap-type segregation prevention powder mixture. At least one of the inner and outer composite powder compacts is made of the wax-type segregation prevention powder.

Abstract: Disclosed is a sintered iron alloy and a method of manufacturing the same. The sintered alloy comprises: an alloy matrix and a lead phase for imparting lubricability to the sintered alloy. The alloy matrix comprises a first alloy phase being composed of 0.5 to 3% nickel by weight, 0.5 to 3% molybdenum by weight, 5.5 to 7.5% cobalt by weight, 0.6 to 1.2% carbon by weight, and the balance iron, and a second alloy phase being composed of 26 to 30% molybdenum by weight, 7 to 9% chromium by weight, 1.5 to 2.5% silicon by weight, and the balance cobalt. The content of the lead phase in the sintered alloy is not more than 3.5% by weight. The lead phase is dispersed in the alloy matrix and a pore which is formed in the alloy matrix. The ratio of the lead dispersed in the alloy matrix to the total lead phase is 60% by weight or more, and the lead phase dispersed in the alloy matrix is particles in which the maximum particle size is 10 .mu.m or less.

Abstract: A high temperature abrasion resistant copper alloy suitable for the material of engine parts such as valve seats and valve guides. The copper alloy comprising aluminum in an amount ranging from 1.0 to 15.0% by weight; at least one element selected from the group consisting of vanadium, niobium and tantalum in the group Va of the periodic table of elements, in an amount ranging from 0.1 to 5.0% by weight; and balance containing copper and impurities. The copper alloy has a structure in which at least one of intermetallic compounds is dispersed. each intermetallic compound contains at least one metal selected from the group consisting of aluminum and copper and at least one element selected from the group consisting of elements of the group Va of the periodic table. This copper alloy exhibits also high oxidation resistance and corrosion resistance at high temperatures.

Abstract: Sintered iron alloy composition and method of manufacturing the same, the sintered alloy composition comprising: about 1.5 to about 2.5% carbon by weight; about 0.5 to about 0.9% manganese by weight; about 0.1 to about 0.2% sulfur by weight; about 1.9 to about 2.5% chromium by weight; about 0.15 to about 0.3% molybdenum by weight; about 2 to about 6% copper by weight; not more than about 0.3% by weight of a metal element material comprising at least one member selected from the group consisting of tungsten and vanadium; an effective content of a first solid lubricant material comprising at least one member selected from the group consisting of magnesium metasilicate minerals and magnesium orthosilicate minerals; and balance iron. This alloy composition is preferably used for making machine parts, such as slide members of valve operating systems for internal combustion engines.

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: A sintered ferro alloy comprises 5 to 25 wt % of one or two elements selected from Mo and W, 2 to 10 wt % of Cr, 0.1 to 0.9 wt % of Si, less than or equal to 0.7 wt % of Mn, less than or equal to 0.05 wt % of P, 0.5 to 2.0 wt % of C, 0.5 to 2.0 wt % of B, 0.1 to 7.0 wt % of at least one element selected from borides of La, Ce, Nd, Sm, Eu, Gd, Yb, Y or Sc, residual Fe, and contaminants. Also the alloy may comprise less than or equal to 20 wt % of at least one element selected from V, Nb, Ta, Ti, Zr, Hf, Co or Ni, if necessary. The alloy is produced by mixing the above mentioned components and pressurizing them in an Fe matrix, then sintering the pressurized mixture at 1150.degree. C. to 1260.degree. C. for 60 min. and reheating after sintering. This alloy has wear and heat resistance and can be utilized as valve seats for internal combustion engines in automotive vehicles.

Abstract: A heat resistant and wear resistant iron-based sintered alloy for use as the material of an engine component part which is subjected to severe temperature and wear conditions. The iron-based sintered alloy is comprised of a matrix formed of metal powder having the composition of alloy steel or high speed tool steel. An additional metal component formed of hard alloy powder is dispersed in the matrix in an amount ranging from 3 to 50% by weight of the matrix. The hard alloy powder contains as major components iron, molybdenum and silicon which improve the wetting property of the hard alloy powder with the matrix and form intermetallic compounds which are high in hardness and excellent in heat and oxidation resistances.

Abstract: A high temperature wear resistant sintered alloy suitable for the material of a valve seat in an automotive vehicle engine. The matrix of the sintered alloy consists essentially of carbon ranging from 0.45 to 1.15% by weight, nickel ranging from 5.4 to 27% by weight, molybdenum ranging form 0.4 to 2.7% by weight, cobalt ranging from 4.2 to 7.2% by weight and balance being substantially iron. The matrix is formed of a mixture of at least one of sorbite structure and bainite structure and austenite structure. Furthermore, the matrix includes hard phase dispersed therein and containing at least silicon, molybdenum and cobalt. The sintered alloy of such a structure can exhibit high strength and wear resistance at high temperatures regardless of type of engine and kind of fuel in case of being used as the material of the valve seat, while maintaining production cost thereof lower.

Abstract: A heat resistant and wear resistant iron-base sintered alloy to be used as the material of a valve seat and a valve face of an engine valve and a waste gate valve of a turbocharger for an internal combustion engine. The iron-base sintered alloy consists essentially of at least one of molybdenum and tungsten, ranging from 3 to 25% by weight, chromium ranging from 1 to 10% by weight, silicon ranging from 0.1 to 0.9% by weight, manganese ranging not more than 0.7% by weight, phosphorus ranging not more than 0.05% by weight, carbon ranging from 0.1 to 2.5% by weight, boron ranging from 0.5 to 2.0% by weight, intermetallic compound of TiAl ranging from 0.3 to 20% by weight, and balance including iron and impurities. In the sintered alloy, carbide, boride and/or carbide boride and TiAl are uniformly dispersed in the matrix, thereby strengthening grain boundary.

Abstract: A wear resistant iron-base sintered alloy consists essentially of at least one selected from the group consisting of molybdenum and tungsten, ranging from 5 to 20% by weight, chromium ranging from 2 to 10% by weight, silicon ranging from 0.1 to 0.9% by weight, manganese ranging not more than 0.7% by weight, phosphorus ranging not more than 0.05% by weight, carbon ranging from 0.1 to 0.8% by weight, boron ranging from 0.5 to 2.0% by weight, and balance including iron and an impurity, so that fine multiple carbide, multiple boride, and/or multiple carbide-boride can be homogeneously dispersed as hard grains in the structure of a matrix, thereby exhibiting excellent wear resistance, scuffing resistance and pitting resistance.

Abstract: A rocker arm of a valve mechanism of an automotive internal combustion engine is composed of a rocker arm tip secured to a rocker arm main body. The rocker arm tip includes a sheet type sintered alloy adhered to a steel substrate. The sintered alloy includes a joining phase of martensite stainless steel, and a hard phase of boride and/or multiple boride of at least one, including iron, of elements capable of forming boride and/or multiple boride. The hard phase is homogeneously dispersed in the joining phase. The sintered alloy contains boron ranging from 3.0 to 5.0% by weight, and the hard phase ranging from 40 to 62% by weight. Additionally, the sintered alloy has a maximum grain size of the boride and/or multiple boride ranging not larger than 50 .mu.m, a Rockwell A-scale hardness number ranging not less than 80, and a deflective strength ranging not lower than 175 kgf/mm.sup.2.