The invention relates to a method for manufacturing a composite component of a timepiece or of a jewelry part, the composite component comprising a porous ceramic part and a metallic material filling the pores of said ceramic part, said method comprising the steps of: providing a porous ceramic preform of the component, providing a metallic material, heating the metallic material to a temperature higher than the melting point of the metallic material, filling the pores of the ceramic preform with the molten metallic material, cooling the metallic material and the ceramic preform to obtain a solidified metallic material in the pores of the ceramic preform, and applying finishing treatments to obtain the composite component, wherein said porous ceramic preform consists essentially of a material selected from the group consisting of Si.sub.3N.sub.4, SiO.sub.2 and mixtures thereof, and said metallic material is selected from the group consisting of gold, platinum, palladium metals and alloys of these metals. The invention relates also to a composite component of a timepiece or of a jewelry part comprising a porous ceramic part and a metallic material filling the pores of said ceramic part, wherein said porous ceramic part consists essentially of a material selected from the group consisting of Si.sub.3N.sub.4, SO.sub.2 and mixtures thereof, and said metallic material which is selected from the group consisting of gold, platinum, palladium metals and alloys of these metals.

A powder metal compact is disclosed. The powder metal compact includes a cellular nanomatrix comprising a nanomatrix material. The powder metal compact also includes a plurality of dispersed particles comprising a particle core material that comprises an MgZr, MgZnZr, MgAlZnMn, MgZnCuMn or MgW alloy, or a combination thereof, dispersed in the cellular nanomatrix.

A method for manufacturing a machine component made of metal-based material is described. The method comprises the steps of: providing a powder blend comprising at least one metal-containing powder material and at least one strengthening dispersor in powder form, wherein the strengthening dispersor in powder form has an average grain size less than an average grain size of the metal-containing powder material; and forming the machine component by an additive manufacturing process using the powder blend.

Embodiments of a method for producing powder mixtures having uniform dispersion of ceramic particles within larger superalloy particles are provided, as are embodiments of superalloy powder mixtures. In one embodiment, the method includes producing an initial powder mixture comprising ceramic particles mixed with superalloy mother particles having an average diameter larger than the average diameter of the ceramic particles. The initial powder mixture is formed into a consumable solid body. At least a portion of the consumable solid body is gradually melted, while the consumable solid body is rotated at a rate of speed sufficient to cast-off a uniformly dispersed powder mixture in which the ceramic particles are embedded within the superalloy mother particles.

An object of the present invention is to provide a spark plug which includes, at at least one of a center electrode and a ground electrode, a tip having excellent spark wear resistance in a high temperature environment, thereby having excellent durability. A spark plug includes a center electrode and a ground electrode disposed with a gap provided between the center electrode and the ground electrode. At least one of the center electrode and the ground electrode includes a tip which defines the gap. The tip includes a metal base material containing Ir as a main component, and oxide particles containing at least one of oxides having a perovskite structure represented by general formula ABO.sub.3 (A is at least one element selected from elements in group 2 in a periodic table, and B is at least one element selected from metal elements). When a cross section of the tip is observed, an area proportion of the oxide particles is not lower than 1% and not higher than 13%.

There is provided an inorganic particle composite body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate, wherein part of the solid material is in at least part of the gaps in the inorganic particle layer. This inorganic particle composite body is produced by a method including a preparation step of preparing an inorganic particle structural body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate; and a filling step of plastically deforming at least part of the solid material contained in the inorganic particle structural body, thereby filling at least part of the gaps in the inorganic particle layer with part of the plastically deformed solid material.

A composite magnetic material includes first particles made of soft magnetic metal and second particles provided between first particles. Each of the second particles includes a first solid phase and a second solid phase. The composite magnetic material exhibits high magnetic characteristics.

An object of the present invention is to provide a spark plug which includes, at at least one of a center electrode and a ground electrode, a tip having excellent spark wear resistance in a high temperature environment, thereby having excellent durability. A spark plug includes a center electrode and a ground electrode disposed with a gap provided between the center electrode and the ground electrode. At least one of the center electrode and the ground electrode includes a tip which defines the gap. The tip includes a metal base material containing Ir as a main component, and oxide particles containing at least one of oxides having a perovskite structure represented by general formula ABO.sub.3 (A is at least one element selected from elements in group 2 in a periodic table, and B is at least one element selected from metal elements). When a cross section of the tip is observed, an area proportion of the oxide particles is not lower than 1% and not higher than 13%.

Embodiments of a method for producing powder mixtures having uniform dispersion of ceramic particles within larger superalloy particles are provided, as are embodiments of superalloy powder mixtures. In one embodiment, the method includes producing an initial powder mixture comprising ceramic particles mixed with superalloy mother particles having an average diameter larger than the average diameter of the ceramic particles. The initial powder mixture is formed into a consumable solid body. At least a portion of the consumable solid body is gradually melted, while the consumable solid body is rotated at a rate of speed sufficient to cast-off a uniformly dispersed powder mixture in which the ceramic particles are embedded within the superalloy mother particles.

The valve seat includes an iron-based sintered alloy subjected to oxidation treatment, which is obtained by subjecting an iron-based sintered alloy including: 4 mass % to 15 mass % of Co particles; and hard particles each containing at least one compound of an intermetallic compound, a carbide, a silicide, a nitride, or a boride that has one or more kinds of elements selected from group 4a to 6a elements in a periodic table, and having a hardness of from 600 HV to 1,600 HV to oxidation treatment, and which has an oxide mainly including triiron tetraoxide (Fe.sub.3O.sub.4) and cobalt oxide (CoO) formed on a surface and in an interior of the iron-based sintered alloy. The iron-based sintered alloy subjected to oxidation treatment has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.