Abstract: An aluminum nitride substrate includes an aluminum nitride sintered body containing a rare earth oxide as a sintering additive component. In the aluminum nitride substrate, a surface thereof is machined so that arithmetic average roughness Ra is 0.5 &mgr;m or less; an aggregate size of the sintering additive component present on the machined surface is 20 &mgr;m or less; and a total aggregate area in a unit area of the machined surface is 5% or less. A metal thin film is deposited on such machined surface with good intimate contact properties, and furthermore deposition accuracy or the like is improved.

Abstract: Wear resistant member for electronic equipment comprises a silicon nitride sintered body that contains conductivity enhancing particles, and has electrical resistivity in the range from 1 to 105 &OHgr;·m. In silicon nitride sintered body, agglomeration of conductivity enhancing particles in which distance between conductivity enhancing particles is less than 1 &mgr;m exists by 30% or less by area ratio per unit area. Wear resistant member is used for a bearing ball or the like, being applied in a rotation actuator of electronic equipment such as a magnetic recorder and optical disk drive. Malfunction of electronic equipment due to static electricity may be cancelled due to electrical resistivity that silicon nitride sintered body has.

Abstract: In ceramic sinter consisting of at least one kind selected from a group consisting of silicon nitride, zirconia, silicon carbide, cermet, SIALON, aluminum nitride and alumina, wear resistant member and electronic component member using thereof, skewness at a contact surface of the ceramic sinter is set at −2 or more and 0 or less, a depth of a micro-crack is set at 5 &mgr;m or less, and in the depth of up to 500 &mgr;m from the surface an area that pores occupy does not exceed 5%. The ceramic sinter as described above can suppress wear of the opponent member. Further, in such ceramic sinter, bonding strength with an element or a metal plate can be heightened to enable to suppress peeling. The electronic components of high reliability can be fabricated accordingly. The present wear resistant member is suitable for sliding member that is used in portions where wear is particularly remarkable.

Abstract: An aluminum nitride substrate includes an aluminum nitride sintered body containing a rare earth oxide as a sintering additive component. In the aluminum nitride substrate, a surface thereof is machined so that arithmetic average roughness Ra is 0.5 &mgr;m or less; an aggregate size of the sintering additive component present on the machined surface is 20 &mgr;m or less; and a total aggregate area in a unit area of the machined surface is 5% or less. A metal thin film is deposited on such machined surface with good intimate contact properties, and furthermore deposition accuracy or the like is improved.

Abstract: Wear resistant member for electronic equipment comprises a silicon nitride sintered body that contains conductivity enhancing particles, and has electrical resistivity in the range from 1 to 105 &OHgr;·m. In silicon nitride sintered body, agglomeration of conductivity enhancing particles in which distance between conductivity enhancing particles is less than 1 &mgr;m exists by 30% or less by area ratio per unit area. Wear resistant member is used for a bearing ball or the like, being applied in a rotation actuator of electronic equipment such as a magnetic recorder and optical disk drive. Malfunction of electronic equipment due to static electricity may be cancelled due to electrical resistivity that silicon nitride sintered body has.

Abstract: A wear and scuff-resistant plunger for use in high pressure fuel system components in internal combustion engines is provided. The plunger, which is formed of a high thermal expansion, high hardness ceramic with a thermal expansion coefficient preferably greater than 6.times.10.sup.-6 /.degree. C. and a hardness preferably greater than 800 Kg/mM.sup.2, maintains a desired optimum minimal diametral clearance while avoiding excessive fuel leakage and efficient plunger function without scuffing or sticking under the high axial, side and pressure loads and variable quality fuels encountered in the fuel system operating environment. Preferred high thermal expansion, high hardness ceramics are zirconia, alumina-zirconia and alumina.

Abstract: A wear and scuff-resistant timing plunger for a timing assembly in a unit fuel injector for an internal combustion engine is provided. The timing plunger is formed of a high thermal expansion ceramic with a thermal expansion coefficient greater than 6.times.10.sup.-6 /.degree. C. and a hardness greater than 800 Kg/mm.sup.2, which maintains a desired diametral clearance and efficient plunger function without scuffing or sticking under the axial, tangential and pressure loads encountered in the fuel injector operating environment. Preferred high thermal expansion ceramics are zirconia, alumina-zirconia and alumina.

Abstract: A high thermal conductive silicon nitride structural member of the present invention contains a rare earth element in the range of 1.0 to 7.5 wt. % calculated as oxide thereof and Li, Na, K, Fe, Ca, Mg, Sr, Ba, Mn and B as impurity cationic elements in a total amount not greater than 0.3 wt. %, and has the thermal conductivity not less than 60 W/(m.K), preferably not less than 80 W/(m.K). Also, a high thermal conductive silicon nitride sintered body consists of silicon nitride particles and a grain boundary phase, a crystal compound phase in the grain boundary phase being not less than 20 vol. %, preferably not less than 50 vol. %, with respect to the entire grain boundary phase, and has the thermal conductivity not less than 60 W/(m.K), preferably not less than 80 W/(m.K).

Abstract: A ceramic-metal composite structure which minimizes tensile ceramic loads and accommodates differences in thermal expansion characteristics between a metal member and a ceramic member without reliance on precise feature control for either member. The composite includes a mechanical retainer which allows a loose fitting relationship between the metal and ceramic members. The ceramic member is secured within a receiving bore in the metal member by the retainer in a manner which eliminates the need for precise machining of the ceramic and metal members. The metal member may be configured to accept either an internal or an external mechanical retainer element. The composite ceramic-metal structure of the present invention finds particular utility in forming a durable wear-resistant interface in internal combustion engine actuator or actuating components, such as compression brake master pistons.

Abstract: In accordance with preferred embodiments of the invention, a disc-shaped contact pad of ceramic material is disposed within a recess formed in the top surface of a metal valve crosshead. The pad is held in the recess by a retainer that clips onto the crosshead. The retainer is designed to maintain only a light pressure on only a narrow shoulder of the pad to keep it seated, and does not, itself, experience any dynamic loading. Furthermore, by the provision of a circumferential clearance between the pad and both the wall of the crosshead recess and the retainer, the need for precision machining of the ceramic material can be avoided. Additionally, a reduction of frictional sliding forces imposed on the crosshead, and in turn upon the valves, by the rocker lever is achieved by the ceramic pad, so that resultant frictional side loading is not imposed on adjacent valve components to a significant extent.

Abstract: A highly wear-resistant plunger assembly for a fuel injector, particularly an open nozzle fuel injector, is provided. The wear-resistant plunger assembly of the present invention includes components formed from wear-resistant materials specifically including, but not limited to, ceramics and metals capable of withstanding the high temperatures and frictional forces produced by prolonged motoring and other potentially adverse engine operating conditions. Different portions of the plunger assembly may be formed from different kinds of wear-resistant materials.

Abstract: A ceramic-metal composite structure which minimizes tensile ceramic loads and accommodates differences in thermal expansion characteristics between a metal member and a ceramic member without reliance on precise feature control for either member. The composite includes a mechanical retainer which allows a loose fitting relationship between the metal and ceramic members. The ceramic member is secured within a receiving bore in the metal member by the retainer in a manner which eliminates the need for precise machining of the ceramic and metal members. The metal member may be configured to accept either an internal or an external mechanical retainer element. The composite ceramic-metal structure of the present invention finds particular utility in forming a durable wear-resistant interface in internal combustion engine actuator or actuating components, such as compression brake master pistons.