NGK SPARK PLUG CO., LTD.

A noble metal tip for a spark plug according to the present invention contains iridium (Ir) in an amount of 50 mass % or more and aluminum (Al) in an amount of 0.1 mass % or more and 5 mass % or less, and further contains rhodium (Rh), wherein a metallographic structure comprised of fiber-like elements R is observed, and the fiber-like elements R of the metallographic structure have an average aspect ratio of 150 or more and have an average length of 25 μm or less in a minor axis direction.

A dehydrogenation reaction catalyst has a perovskite structure represented by the formula (A 1-x A′ x ) (Zr 1-y-z B y B′ z ) O 3 , where A is at least one element selected from alkaline earth metals, A′ is at least one of lanthanum (La) and yttrium (Y), B is at least one of titanium (Ti) and cerium (Ce), and B′ is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)). Further, x, y, and z satisfy 0≤x≤0.4, 0.3≤(1−z)≤1, 0≤y, and 0<(1−y−z).

A spark plug that can reduce variation in a discharge point. The spark plug includes: a center electrode; a metal shell insulating and holding the center electrode; and a ground electrode including a base material having one end portion connected to the metal shell, and a tip connected to another end portion of the base material. The tip has a discharge surface opposed to the center electrode with a spark gap therebetween. The discharge surface has a quadrangular shape and is chamfered at four sides thereof. Only a first side which is one of the four sides is provided with a C chamfer.

A spark plug which includes an insulator having an axial hole extending along an axial line, a metallic shell disposed around the insulator, and a center electrode disposed in the axial hole to be located on the forward end side of the axial line is provided. The insulator has a step portion provided on the outer circumferential surface thereof and facing toward the forward end side. The metallic shell has a receiving surface provided on the inner circumferential surface thereof and facing toward the rear end side and with which the step portion is engaged via a packing. A portion of the step portion on the outer circumferential side is a first curved surface being convex toward the forward end side, and a portion of the step portion on the inner circumferential side of the first curved surface is a second curved surface being convex toward the rear end side.

A gas sensor ( 1 ) including a sensor element ( 10 ); a metallic shell ( 138 ); a tubular outer surface member ( 190 ) attached directly or indirectly to the metallic shell, constitutes an outer surface of the gas sensor, and extends toward a rear end side in relation to the metallic shell; and a tubular protection member ( 210, 220 ) which is detachably fixed to a fixation region C 1 , C 2 of an outer circumference of the outer surface member. The protection member includes a first arc portion ( 212 ), a second arc portion ( 222 ), and a fixation portion ( 214,224 ) brought into contact with and is fixed to the fixation region. When the protection member fixed to the outer circumference of the outer surface member by fixing the fixation portion to the fixation region is viewed in the axial O direction, the first arc portion and the second arc portion cover in total at least 90% of the entire circumference of the outer surface of the outer surface member.

In an electrochemical gas sensor ( 10 ), a first sensing element ( 21 ) is stored in a first storage portion ( 31 ). A moisture permeable film ( 24 ) is disposed in a first introduction inlet ( 31 A) of the first storage portion ( 31 ). The moisture permeable film ( 24 ) substantially prevents a to-be-detected gas from permeating therethrough. A second sensing element ( 22 ) is disposed in a space into which water vapor and the to-be-detected gas contained in a target gas flow. In such a configuration, the electrochemical gas sensor ( 10 ) is capable of detecting a to-be-detected gas having a concentration of 0 or more and 1 ppm or less.

A sintered body and cutting tool, the sintered body ( 2 ) including: a first hard particle ( 10 ) containing TiCN; a second hard particle ( 20 ) containing (Ti, M) (C, N); a third hard particle ( 30 ) including a core portion ( 31 ) containing TiCN, and a peripheral portion ( 32 ) enclosing the core portion ( 31 ) and containing (Ti, M) (C, N) each as main components; a particle ( 40 ) containing at least one of Al, Zr, and Si; and a binding phase ( 50 ) containing at least one of Co and Ni and at least one of Re and Ru, and has a thickness of not greater than 5 nm. The third hard particle ( 30 ) has, in the core portion ( 31 ), a particle ( 33 ) containing at least one selected from Co, Ni, Re, and Ru, and has a dislocation ( 34 ) in each of the core portion ( 31 ) and the peripheral portion ( 32 ).

Spark plug has center electrode having leg portion extending in an axis direction, brim portion located at rear end side with respect to the leg portion and protruding outwards in a radial direction with respect to the leg portion and connecting portion connecting the leg portion and the brim portion; insulator having penetration hole and supporting the center electrode; and seal member filling the penetration hole and fixing the brim portion and the insulator. The center electrode satisfies “(D 1 -D 2 )/D 1 ≤0.06”, where a maximum value of a radius of the brim portion is D 1 , and a minimum value of the radius of the brim portion is D 2 , also satisfies “L 2 /L 1 ≤0.30”, where a size of the center electrode along the axis direction is L 1 , and a size along the axis direction from boundary between the connecting portion and the leg portion to a center of gravity of the center electrode is L 2.

A complex oxide ceramic according to an embodiment is a complex oxide ceramic including a rare earth element and at least one element selected from among molybdenum, tungsten, and vanadium. An example of the rare earth element is at least one species selected from among La, Ce, and Gd.

There is provided a wavelength conversion member including: a fluorescent body and a reflective film. The fluorescent body is configured to emit fluorescence by an excitation light and has an incident surface into which the excitation light comes and a rear surface which faces the incident surface. The reflective film is arranged on a side of the rear surface of the fluorescent body and includes a metal layer and ceramic particles dispersed in the metal layer. The ceramic particles are crystalline, and a melting point of the ceramic particles is higher than a melting point of a metal constructing the metal layer.