Ngk Spark Plug Company, Limited

Niterra Co., Ltd.

Sumitomo Electric Industries, Limited

Hitachi Metals, Ltd.

Ngk Spark Pulg Co., Ltd.

Osamu Yoshimoto

Wataru Matsutani

Tomoo Tanaka

Yoshihiro Matsubara

Kenji Nunome

Takehito Kuno

Tomonori Kanemaru

Akira Suzuki

Mamoru Musasa

Takaaki Kikai

Tomo-o Tanaka

Tsutomu Shibata

Daisuke Sumoyama

Kazuyoshi Torii

Naomichi Miyashita

Yoshihiro Nakai

Toshihiro Uehara

Taichiro Nishikawa

Masahiro Inoue

Tsuneyuki Ito

Kazuo Yamazaki

Toru Tanji

Norihide Kachikawa

Masayuki Segawa

Kengo Hattori

Shinji Ban

Satoko Ito

Ryuichi Arakawa

Tomo-O Tanaka

Yohihiro Nakai

A ceramic sintered body contains a first particular element consisting of five or six elements selected from among titanium (Ti), vanadium (V), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (Ta), and tungsten (W); a second particular element consisting of one element selected from yttrium (Y) and aluminum (Al); and elemental carbon (C). The total amount of the first particular element, the second particular element, and elemental carbon is 98 at % or more. The ceramic sintered body has a plurality of microstructures having respective compositions different from one another. One of the plurality of microstructures includes a solid solution containing at least three members of the first particular element.

Ceramic sintered body and plasma-generating electrode

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.

Noble metal tip for spark plug, electrode for spark plug, and spark plug

A joining layer of a joined body includes a joining material which contains, as a main component, a metal having a surface tension of 1000 mN/m or less at its melting point, and a metal layer which has a plurality of pores formed therein and in which at least some of the pores are impregnated with the joining material.

Joined body, holding device, and electrostatic chuck

An electrode material for at least one of a center electrode () and a ground electrode () provided with a chip () for use in a spark plug (). The electrode material contains Ni as a principal component, and has a Si content of from 0.50% to 1.0% by mass, an Al content of from 0.2% to 2.0% by mass, a Cr content of from 12% to 34% by mass, a rare-earth element or the like content of from 0.03% to 0.2% by mass, a Fe content of more than 0% but not more than 20% by mass, a C content of not more than 0.10% by mass, and a Mn content of not more than 1.0% by mass. The total content of Si and Al is not less than 0.80% by mass, and less than one tenth of the Cr content.

Electrode material and spark plug

A spark plug having a tip provided on at least one of a center electrode and a ground electrode. The spark plug includes a center electrode and a ground electrode disposed providing a gap with the center electrode. At least one of the center electrode and the ground electrode includes a tip forming the gap. The tip has a main constituent of Ir. The tip contains Rh of 7 mass % or more to 31 mass % or less, Ru of 5 mass % or more to 20 mass % or less, and Pt of one-twentieth or more to one-half or less of a Ru content.

Spark plug

A spark plug including a center electrode; an insulator; a metallic shell; and a ground electrode, wherein at least one of the center electrode and the ground electrode has thereon an intermediate member which connects the center electrode or the ground electrode to a noble metal tip. The intermediate member has a tip-bonding portion to which the noble metal tip is bonded, and an electrode-bonding portion which has a diameter greater than that of the tip-bonding portion, and which is bonded to the center electrode or the ground electrode. The intermediate member contains nickel (Ni) as a main component, and also contains chromium (Cr) in an amount of 15 to 25 wt. %. The intermediate member contains, in a surface portion thereof, silicon (Si) in an amount per unit volume of 0.04 mg/mmto 0.12 mg/mm, and aluminum (Al) in an amount per unit volume of 0.03 mg/mmto 0.10 mg/mm.

A spark plug is provided with: a central electrode; a ground electrode forming a spark discharge gap with the center electrode; and a chip welded to at least one of the electrodes. The chip has a thermal expansion coefficient smaller than a thermal expansion coefficient of the electrode to which the chip is welded, and the difference between the content A (mass %) of a noble metal component in the chip and the content B (mass %) of a noble metal component in the electrode (A&#x2212;B) is 50 mass % or more. In an intermediate layer between the chip and the electrode, holes are present. When the length of a boundary between the chip and the intermediate layer is L (mm), and the length of the holes in a direction along the boundary of the chip and the intermediate layer is N (mm), 0.1&#x2266;N/L&#x2266;0.4.

A spark plug capable of preventing a separation of a noble metal tip and capable of extending a service-life of the spark plug.

Spark plug for internal combustion engine and method of manufacturing the same

It is an object of the present invention to provide a spark plug having a ground electrode joined securely by electric resistance welding. The spark plug includes a cylindrical metal shell and a ground electrode joined by electric resistance welding to an end portion of the metal shell. The metal shell has a high hardness region formed with a Vickers hardness of 3&#xd7;10to 5&#xd7;10Hv in the end portion thereof in such a manner that the high hardness region, when viewed in cross section along a plane including an axis of the spark plug and an axis of the ground electrode, has a length d of 0.3 to 0.8 mm from a ground electrode side welding boundary to a metal shell side welding boundary in a direction of load applied during the electric resistance welding.

A spark plug () includes a metallic shell () and a ground electrode () resistance-welded to the metallic shell (). The ground electrode () is formed from a metal material in which precipitates PR containing at least one of an oxide, an intermetallic compound, etc., are precipitated in grain boundaries. The diameter of an equivalent circle of a precipitate PR having the greatest area is 50 &#x3bc;m or less, and the shortest distance between the precipitates PR is 2 &#x3bc;m or greater. The area occupied by the precipitates PR on the section of the heat-affected zoneA is equal to 65% or more the area occupied by the precipitates PR (the diameter of an equivalent circle of a precipitate PR having the greatest area) on a section of the normal zoneB.

A spark plug including a center electrode and a ground electrode having a core portion and an outer layer covering the core portion, the core portion being formed from a material having a thermal conductivity higher than that of the outer layer. At least a portion in which thickness of the outer layer is 0.5 mm or less is present at a cross-section perpendicular to a direction in which the ground electrode is extended. Further, the composition of the electrode material forming the outer layer is as follows: Ni is 96 mass % or more, total of at least one kind selected from Y and rare earth elements is 0.05 mass % or more, Al is 0.5 mass % or less, and Si is 0.5 mass % or more and 1.5 mass % or less, where the total of Ni, Y, rare earth elements, Al, Si does not exceed 100 mass %.

A spark plug having a center electrode; a ground electrode provided so as to form a gap between the ground electrode and the center electrode; and a tip provided on at least one of a distal end portion of the ground electrode and a front end portion of the center electrode, the end portions facing each other, characterized in that the tip contains an element group M (M consists of at least one species of Pt and Rh) in an amount of 3 mass % to 35 mass %, and an element group L (L consists of at least one species of Ir, Ru, and Pd) in an amount of 0 mass % to 15 mass %; the total amount of the element group M and the element group L is at most 35 mass %; and the total amount of Ni, the element group M, and the element group L is at least 94 mass %.

A spark plug including a center electrode and a ground electrode having a gap between the center electrode and the ground electrode, the ground electrode has an outer layer which is formed from an Ni-based alloy and a core portion which is covered by the outer layer and formed from a material having a thermal conductivity higher than that of the outer layer. Further, the melting point of the Ni-based alloy forming the outer layer is 1150&#xb0; C. or more and 1350&#xb0; C. or less.

A ground electrode () and a noble-metal chip () are joined via a weld portion () formed by fusing and mixing an Ni alloy and a Pt alloy. A plurality of acicular or rhizoid microcracks () are formed in the weld portion (). As viewed on a section of the weld portion (), the average length of the microcracks is 50 &#x3bc;m to 500 &#x3bc;m, and the average aspect ratio (shorter dimension/longer dimension) of the microcracks is 0.05 or less. At least one of the Ni alloy used to form the ground electrode () and the Pt alloy used to form the noble-metal chip () contains as an additive at least one of elements belonging to Groups 3A and 4A of the Periodic Table and oxides of these elements.

Spark plug for internal combustion engine

A spark plug which exhibits improved resistance to high-temperature oxidation of an electrode, and improved resistance to spark-induced erosion of, improved resistance to oxidation of, and improved joining reliability of a tip joined to the electrode. A spark plug has spark members; each of the spark members has a weight of 1.5 mg or more; and a center electrode and a ground electrode contain Ni as a main component, C in an amount of 0.005% by mass to 0.10% by mass, Si in an amount of 1.05% by mass to 3.0% by mass, Mn in an amount of 2.0% by mass or less, Cr in an amount of 20% by mass to 32% by mass, and Fe in an amount of 6% by mass to 16% by mass.

Growing community of inventors

Inazawa, Japan

Osamu Yoshimoto