Abstract: A powder for molding is a mixture of first constituent particles, which are made up of first metal base particles, and second constituent particles, which are made up of second metal base particles. A first lubricant concentration that is a mass proportion of a first internal lubricant adhered to the surface of the first metal base particles with respect to the total of the first constituent particles, is greater than a second lubricant concentration that is a mass proportion of a second internal lubricant that is adhered to the surface of the second metal base particles with respect to the total of the second constituent particles.

Abstract: An iron-based sintered alloy of the present invention is an iron-based sintered alloy, which is completed by sintering a powder compact made by press forming a raw material powder composed of Fe mainly, and is such that: when the entirety is taken as 100% by mass, carbon is 0.1-1.0% by mass; Mn is 0.01-1.5% by mass; the sum of the Mn and Si is 0.02-3.5% by mass; and the major balance is Fe. It was found out that, by means of an adequate amount of Mn and Si, iron-based sintered alloys are strengthened and additionally a good dimensional stability is demonstrated. As a result, it is possible to suppress or obsolete the employment of Cu or Ni, which has been believed to be essential virtually, the recyclability of iron-based sintered alloys can be enhanced, and further their cost reduction can be intended.

Abstract: A powder for molding is a mixture of first constituent particles, which are made up of first metal base particles, and second constituent particles, which are made up of second metal base particles. A first lubricant concentration that is a mass proportion of a first internal lubricant adhered to the surface of the first metal base particles with respect to the total of the first constituent particles, is greater than a second lubricant concentration that is a mass proportion of a second internal lubricant that is adhered to the surface of the second metal base particles with respect to the total of the second constituent particles.

Abstract: A piston for in-cylinder fuel-injection type internal combustion engine includes a piston body, a low thermal conductor, and a piston head. The low thermal conductor is disposed on the top of the piston body. The low thermal conductor includes a low thermally-conductive substrate, and a coating layer. The low thermally-conductive substrate has opposite surfaces. The coating layer includes alumina fine particles (Al2O3). The coating layer is adhered on at least a part one of the opposite surfaces of the low thermally-conductive substrate that makes a cast-buried or enveloped surface to be cast buried or enveloped in the piston head.

Abstract: There is provided an iron-based sintered material resistant to the metal fatigue developing from the voids therein functioning as the initial points and improved in the strength and machinability thereof. An iron-based sintered material, including a mixed structure of martensite, bainite, and pearlite and multiple voids formed in the mixed structure, wherein the ratio of martensite and bainite in the mixed structure is 70% or more; the ratio of martensite and/or bainite in the mixed structure forming the void surface is 90% or more; and the density of the iron-based sintered material is 7.4 g/cm3 or more.

Abstract: A process for producing ferrous sintered alloy according to the present invention is characterized in that it is equipped with: a compaction step of pressure compacting a raw-material powder in which an Fe-system powder is mixed with a reinforcement powder, thereby turning the raw-material powder into a powder compact; and a sintering step of heating this powder compact in an oxidation preventive atmosphere, thereby sintering the powder compact; and said reinforcement powder is an Fe—Mn—Si—C powder comprising an Fe alloy or an Fe compound that includes: Mn in an amount of from 58 to 70%; Si in an amount making a compositional ratio of the Mn with respect to the Si (i.e., Mn/Si) that is from 3.3 to 4.6; and C in an amount of from 1.5 to 3%; when the entirety is taken as 100% by mass. This Fe—Mn—Si—C powder is procurable inexpensively relatively; besides, ferrous sintered alloys, which are obtained using that, are better in terms of various characteristics than are conventional ferrous sintered alloys.

Abstract: A ferrous sintered alloy includes a sintered raw-material powder that is made of an Fe—Cr—Mo-system powder, a carbon-system powder and an Mn—Si-system powder before sintering. The ferrous sintered alloy exhibits a density of 7.4 g/cm3 or more, and has a metallic structure that includes martensite and bainite. In the metallic structure, the martensite accounts for an area proportion of 40% or less when the entirety of the metallic structure is taken as 100% by area. Moreover, the martensite exhibits a particle diameter of 20 ?m or less. The ferrous sintered alloy is good in terms of machinability.

Abstract: An iron-based sintered alloy of the present invention is an iron-based sintered alloy, which is completed by sintering a powder compact made by press forming a raw material powder composed of Fe mainly, and is such that: when the entirety is taken as 100% by mass, carbon is 0.1-1.0% by mass; Mn is 0.01-1.5% by mass; the sum of the Mn and Si is 0.02-3.5% by mass; and the major balance is Fe. It was found out that, by means of an adequate amount of Mn and Si, iron-based sintered alloys are strengthened and additionally a good dimensional stability is demonstrated. As a result, it is possible to suppress or obsolete the employment of Cu or Ni, which has been believed to be essential virtually, the recyclability of iron-based sintered alloys can be enhanced, and further their cost reduction can be intended.

Abstract: A piston for in-cylinder fuel-injection type internal combustion engine includes a piston body, a low thermal conductor, and a piston head. The low thermal conductor is disposed on the top of the piston body. The low thermal conductor includes a low thermally-conductive substrate, and a coating layer. The low thermally-conductive substrate has opposite surfaces. The coating layer includes alumina fine particles (Al2O3). The coating layer is adhered on at least a part one of the opposite surfaces of the low thermally-conductive substrate that makes a cast-buried or enveloped surface to be cast buried or enveloped in the piston head.

Abstract: There is provided an iron-based sintered material resistant to the metal fatigue developing from the voids therein functioning as the initial points and improved in the strength and machinability thereof. An iron-based sintered material, including a mixed structure of martensite, bainite, and pearlite and multiple voids formed in the mixed structure, wherein the ratio of martensite and bainite in the mixed structure is 70% or more; the ratio of martensite and/or bainite in the mixed structure forming the void surface is 90% or more; and the density of the iron-based sintered material is 7.4 g/cm3 or more.

Abstract: An iron-based sintered alloy of the present invention is an iron-based sintered alloy, which is completed by sintering a powder compact made by press forming a raw material powder composed of Fe mainly, and is such that: when the entirety is taken as 100% by mass, carbon is 0.1-1.0% by mass; Mn is 0.01-1.5% by mass; the sum of the Mn and Si is 0.02-3.5% by mass; and the major balance is Fe. It was found out that, by means of an adequate amount of Mn and Si, iron-based sintered alloys are strengthened and additionally a good dimensional stability is demonstrated. As a result, it is possible to suppress or obsolete the employment of Cu or Ni, which has been believed to be essential virtually, the recyclability of iron-based sintered alloys can be enhanced, and further their cost reduction can be intended.

Abstract: An insulation film whose requisite constituent elements are first elements and a second element. The first elements include B, P, O and Fe. The second element can generate cations whose hexa-coordinated ion radius, defined by Shannon, R. D., is 0.073 nm or more, and which are bivalent or more. Since the second element having a large ion radius is incorporated into network formers made from the first elements, it is possible to improve the heat resistance of the insulation film.

Abstract: A process for compacting a green compact includes the steps of applying a higher fatty acid-based lubricant to an inner surface of a die, filling a raw material powder whose major component is an active metallic element into the die, compacting the raw material powder by warm pressurizing to make a green compact, and ejecting the green compact from the die, whereby the resulting green compact has a high density. It is possible to form active metallic powders including an active metallic element such as Ti and Al by pressurizing by high pressures, and to produce high-density green compacts which have not been available conventionally.

Abstract: An insulation film whose requisite constituent elements are first elements and a second element. The first elements include B, P, O and Fe. The second element can generate cations whose hexa-coordinated ion radius, defined by Shannon, R. D., is 0.073 nm or more, and which are bivalent or more. Since the second element having a large ion radius is incorporated into network formers made from the first elements, it is possible to improve the heat resistance of the insulation film.

Abstract: A method and apparatus for filling a cavity with powder wherein a pipe having holes for discharging gas is disposed in a powder box and gas is discharged into the powder in the powder box as the powder enters the cavity so that particles of the powder are movable relative to each other. Due to the gas discharge, the powder can enter the cavity smoothly without whirling up in the cavity and settling unevenly, so that a filling time period is shortened and a particle size distribution in the cavity is uniform.