Abstract: A ground electrode for a spark plug includes a ground electrode body arranged to face a center electrode of the spark plug. The ground electrode includes a discharge portion mounted on the ground electrode body to face the center electrode with a spark gap between the discharge portion and the center electrode. The discharge portion is made of a platinum-based alloy of platinum, rhodium, and nickel. A first mass percent of the rhodium contained in the platinum-based alloy of the platinum, the rhodium, and the nickel is within a first range from 2 wt % to 20 wt % inclusive. A second mass percent of the nickel contained in the platinum-based alloy of the platinum, the rhodium, and the nickel being within a second range from 2.5 wt % to 12 wt % inclusive.

Abstract: An iridium alloy includes iridium, platinum, and tantalum. A content of the platinum in the iridium alloy falls within a range from 5 wt % to 30 wt %, and a content of the tantalum in the iridium alloy falls within a range from 0.3 wt % to 5 wt %.

Abstract: A ground electrode for a spark plug includes a ground electrode body arranged to face a center electrode of the spark plug. The ground electrode includes a discharge portion mounted on the ground electrode body to face the center electrode with a spark gap between the discharge portion and the center electrode. The discharge portion is made of a platinum-based alloy of platinum, rhodium, and nickel. A first mass percent of the rhodium contained in the platinum-based alloy of the platinum, the rhodium, and the nickel is within a first range from 2 wt % to 20 wt % inclusive. A second mass percent of the nickel contained in the platinum-based alloy of the platinum, the rhodium, and the nickel being within a second range from 2.5 wt % to 12 wt % inclusive.

Abstract: An iridium alloy includes iridium, platinum, and tantalum. A content of the platinum in the iridium alloy falls within a range from 5 wt % to 30 wt %, and a content of the tantalum in the iridium alloy falls within a range from 0.3 wt % to 5 wt %.

Abstract: A spark plug includes a center electrode held inside an insulator, a ground electrode that is provided on a housing holding the insulator and faces the center electrode, and a composite chip formed on at least one of the electrodes. In the composite chip, a core having a mount integral with an electrode base material is formed from a Ni alloy material, and a surface layer having a discharge portion covering a protrusion end surface of the core and a side surface coating covering a side surface is formed from a Pt alloy material. The coating thickness S of the side surface coating in the radial direction, the outer diameter D1 of the discharge portion, and the coating length L1 of the side surface coating in the axial direction satisfy: S?D1/20+L1/10?0.005 mm.

Abstract: A spark plug includes a center electrode held inside an insulator, a ground electrode that is provided on a housing holding the insulator and faces the center electrode, and a composite chip formed on at least one of the electrodes. In the composite chip, a core having a mount integral with an electrode base material is formed from a Ni alloy material, and a surface layer having a discharge portion covering a protrusion end surface of the core and a side surface coating covering a side surface is formed from a Pt alloy material. The coating thickness S of the side surface coating in the radial direction, the outer diameter D1 of the discharge portion, and the coating length L1 of the side surface coating in the axial direction satisfy: S?D1/20+L1/10?0.005 mm.

Abstract: An ignition plug for an internal combustion engine includes an electrode protrusion that protrudes from an electrode base material of a ground electrode toward a discharge gap. The electrode protrusion has a base part that is integrated with the electrode base material and a cover part that is joined to the base part and faces the discharge gap. The base part has an end surface facing a protrusion direction of the base part and a side peripheral surface. An outer edge of the end surface has a curved surface. The cover part is formed from a precious metal or a precious metal alloy having a lower linear expansion coefficient than that of a material for forming the base part and covers at least a part of the side peripheral surface and the end surface of the base part. While the ignition plug is attached to an internal combustion engine and the electrode protrusion is heated and then cooled, a projection is formed on an outer surface of a portion covering the side peripheral surface of the base part.

Abstract: An ignition plug for an internal combustion engine includes an electrode protrusion that protrudes from an electrode base material of a ground electrode toward a discharge gap. The electrode protrusion has a base part that is integrated with the electrode base material and a cover part that is joined to the base part and faces the discharge gap. The base part has an end surface facing a protrusion direction of the base part and a side peripheral surface. An outer edge of the end surface has a curved surface. The cover part is formed from a precious metal or a precious metal alloy having a lower linear expansion coefficient than that of a material for forming the base part and covers at least a part of the side peripheral surface and the end surface of the base part. While the ignition plug is attached to an internal combustion engine and the electrode protrusion is heated and then cooled, a projection is formed on an outer surface of a portion covering the side peripheral surface of the base part.

Abstract: An electrode material is composed of at least 0.2 mass % and at most 1.0 mass % of Y, at least 0 mass % and at most 0.2 mass % of Al, at least 0.2 mass % and at most 1.6 mass % of Si, at least 0.05 mass % and at most 1.0 mass % of Cr, at least 0.05 mass % and at most 0.5 mass % of Ti, at least 0.1 mass % and at most 0.5 mass in total of one or more elements selected from among Yb, Sb, Ir, Zr, Hf, Pt, Re, Pd, Rh, Ru, Nb, V, W, Mo, and Ta, and a remainder composed of Ni and an inevitable impurity.

Abstract: An electrode material is composed of at least 0.2 mass % and at most 1.0 mass % of Y, at least 0 mass % and at most 0.2 mass % of Al, at least 0.2 mass % and at most 1.6 mass % of Si, at least 0.05 mass % and at most 1.0 mass % of Cr, at least 0.05 mass % and at most 0.5 mass % of Ti, at least 0.1 mass % and at most 0.5 mass in total of one or more elements selected from among Yb, Sb, Ir, Zr, Hf, Pt, Re, Pd, Rh, Ru, Nb, V, W, Mo, and Ta, and a remainder composed of Ni and an inevitable impurity.

Abstract: The purpose of the present invention is to provide an alcoholic solvent, in which FeCo-based particles becoming a soft magnet are improved, for enhancing properties of a magnetic material using no heavy rare earth elements, and is to provide a sintered magnet produced by using it.

Abstract: An assembly includes an engine main body, a spark plug and a gasket. The spark plug is mounted to the engine main body by tightening a male-threaded portion of the spark plug into a female-threaded portion of the engine main body with the gasket elastically deformed between a seat surface of the engine main body and a seating surface of the spark plug. The gasket is made of a metallic material whose yield stress or 0.2% proof stress is not lower than 200 N/mm2. The gasket has first and second contact surfaces respectively in contact with the seating surface of the spark plug and the seat surface of the engine main body. The first and second contact surfaces of the gasket are each formed as a part of a curved surface that has a convex shape, and are offset from each other in a radial direction of the spark plug.

Abstract: A spark plug has a center electrode and an earth electrode. The center electrode is faced to the earth electrode so that a spark discharging gap is formed between the center electrode and the earth electrode. An electrode chip is formed on at least one of the center electrode and the earth electrode. The electrode chip has a composition containing 40 to 60 mol % of aluminum and iridium as a remainder thereof. In the composition of the electrode chip, it is possible to replace part of the iridium with 1 to 20 mol % of at least one metal selected from nickel, iron, cobalt, platinum and rhodium.

Abstract: A spark plug for use in an internal combustion engine has a center electrode, an earth electrode, and an electrode chip formed on at least one of the center electrode and the earth electrode. A spark discharge gap is formed between the center electrode and the earth electrode. The electrode chip has a base section, a chromium rich layer formed on at least a part of the base section, and a diffusion layer formed between the base section and the chromium rich layer. The base section contains chromium within a range of 5 to 45 mass %, an element X within a range of 0.5 to 25 mass %, and a remainder composed of tungsten and unavoidable impurity. The chromium rich layer is larger in content of chromium than the base section. The element X contained in the base section is comprised of at least one of molybdenum, silicon, aluminum and lead.

Abstract: In a spark plug, a center electrode includes a base member and a discharge chip that has a higher melting point than the base member. The base member and the discharge chip are joined to each other by both a weld and a diffusion layer. The weld is formed, by fusion welding, along an outer periphery of an interface between the base member and the discharge chip into an annular shape. The weld is made up of those parts of the base member and the discharge chip which are molten and mixed together during the fusion welding and solidified after the fusion welding. The diffusion layer is formed radially inside the annular weld. The diffusion layer is made up of those parts of the base member and the discharge chip which are diffused into each other across the interface between the base member and the discharge chip.

Abstract: In a spark plug, a center electrode includes a base member and a discharge chip that has a higher melting point than the base member. The base member and the discharge chip are joined to each other by both a weld and a diffusion layer. The weld is formed, by fusion welding, along an outer periphery of an interface between the base member and the discharge chip into an annular shape. The weld is made up of those parts of the base member and the discharge chip which are molten and mixed together during the fusion welding and solidified after the fusion welding. The diffusion layer is formed radially inside the annular weld. The diffusion layer is made up of those parts of the base member and the discharge chip which are diffused into each other across the interface between the base member and the discharge chip.

Abstract: A spark plug for an internal combustion engine is provided, which includes a housing, an insulation porcelain, a center electrode and a ground electrode. At least one of a tip portion of the center electrode and an opposing portion of the ground electrode is provided with a projection portion. At least one of the projection portions has a cross section perpendicular to the axial direction of the plug, the cross section having a minimum curvature radius portion and being in a specific shape that satisfies a predetermined requirement. The requirement is that, when a first straight line, a first line segment and a second straight line are provided, and when the cross section is divided into a first region and a second region by the second straight line, the second region has an area larger than the area of the first region.

Abstract: The temperature sensor 1 is equipped with a temperature sensitive device 2 to be disposed inside an exhaust pipe of an internal combustion engine, signal lines 31 connected at a top end side to the temperature sensitive device 2 and at a rear end side to leads for connection with an external circuit, an inner member 18 having a sheath pin 3 in which the signal lines 31 are disposed, and an outer member 13 disposed to cover at least a portion of an outer periphery of the inner member 18. The outer member 13 includes a fixed portion (rib 6) to be fixed to an upper wall of the exhaust pipe, a retainer portion 132 retaining the inner member 18, and an extending portion 131 formed closer to a top end side than the retainer portion 132.

Abstract: A spark plug for an internal combustion engine is provided, which includes a housing, an insulation porcelain, a center electrode and a ground electrode. At least one of a tip portion of the center electrode and an opposing portion of the ground electrode is provided with a projection portion. At least one of the projection portions has a cross section perpendicular to the axial direction of the plug, the cross section having a minimum curvature radius portion and being in a specific shape that satisfies a predetermined requirement. The requirement is that, when a first straight line, a first line segment and a second straight line are provided, and when the cross section is divided into a first region and a second region by the second straight line, the second region has an area larger than the area of the first region.

Abstract: A mold is designed by calculating a distribution of a contact surface pressure of a mating surface of a mold under a casting condition, and setting a machining amount of the mating surface of the mold based on the calculated distribution of the contact surface pressure.