Abstract: A composite member includes a substrate composed of a composite material containing a metal and a non-metal. One surface of the substrate has spherical warpage of which radius of curvature R is not smaller than 5000 mm and not greater than 35000 mm. A sphericity error is not greater than 10.0 ?m, the sphericity error being defined as an average distance between a plurality of measurement points on a contour of a warped portion of the substrate and approximate arcs defined by the plurality of measurement points. The substrate has a thermal conductivity not lower than 150 W/m·K and a coefficient of linear expansion not greater than 10 ppm/K.

Abstract: A composite member includes a substrate composed of a composite material containing a metal and a non-metal. One surface of the substrate has spherical warpage of which radius of curvature R is not smaller than 5000 mm and not greater than 35000 mm. A sphericity error is not greater than 10.0 ?m, the sphericity error being defined as an average distance between a plurality of measurement points on a contour of a warped portion of the substrate and approximate arcs defined by the plurality of measurement points. The substrate has a thermal conductivity not lower than 150 W/m·K and a coefficient of linear expansion not greater than 10 ppm/K.

Abstract: An AlN sintered compact includes AlN crystal grains and a grain boundary phase, and the grain boundary phase is lower in Vickers hardness than the AlN crystal grains.

Abstract: An AlN substrate with excellent heat transfer efficiency between it and another member to be bonded to a bonding surface of the AlN substrate. The AlN substrate is composed of an AlN sintered body containing group 2A and 3A elements, and the surface roughness Ra of the bonding surface is 3 nm or less, and, in voids having long diameters of 0.25 ?m or more, the mean value is 1.5 ?m or less, and the maximum value is 1.8 ?m or less. A method for producing the AlN substrate includes sintering a precursor formed of a sintering material that contains 88.7 to 98.5 mass % with respect to AlN, 0.01 to 0.3 mass % with respect to a group 2A element in oxide equivalent, and 0.05 to 5 mass % with respect to a group 3A element in oxide equivalent to form a sintered body, and applying HIP treatment onto the sintered body.

Abstract: An object of the present invention is to provide a wear-resistant sliding part with a wear-resistant member to reduce wear of contacting portions of two parts which moves in linkage with each other such as a valve bridge and a rocker arm in a valve train system of a diesel engine, wherein the wear-resistant member is held in a recess of a receiving part securely not to fall off and allowed in the recess to rotate and move in the parallel direction to its bottom surface. Also the wear-resistant member is arranged with at least one of the following: a chamfer provided at the perimeter of bottom surface; the bottom surface with the flatness from 0.05 to 0.20 ?m and a convex shape of a raised-up outer side; and at least one of the bottom, side, and top surfaces having surface roughness (Ra) of 0.2 ?m or less.

Abstract: A method of producing a silicon nitride ceramic component, comprising: grinding a silicon nitride sintered body comprising .alpha.--Si.sub.3 N.sub.4 having an average grain size of 0.5 .mu.m or smaller and .beta.'-sialon having an average grain size of 3 .mu.m or smaller in major axis and 1 .mu.m or smaller in minor axis into a predetermined size with a surface roughness of 1-7 .mu.m in ten-point mean roughness; heat treating the same at temperature range of 800.degree.-1200.degree. C. in the air; and standing it to allow to be cooled, whereby providing a residual stress in the ground surface before and after the heat treating as a residual compressive stress at a ratio of 1 or higher of the residual compressive stress after the heat treating to that before the heat treating (residual compressive stress after the heat treating/residual compressive stress before the heat treating), preferably 5 or more.

Abstract: A ceramic die for cutting and shaping lead frames, in which at least a working section thereof is made of a specific ceramic material having an iron and cobalt content of less than 100 ppm in total. The ceramic die can be formed in a complex shape with a high precision and has a prolonged lifetime because of its superior mechanical properties, such as high wear resistance and high strength, and less probability of adhesion of foreign matter such as solder or the lead frame material thereto. Even if the solder or lead frame material is adhered onto the die, the adhered matter can be removed through a simple procedure in a shortened time. The die is further improved by depositing a hard carbon film onto the surface of the working section.

Abstract: A grind-machining method of ceramic materials characterized in that a peripheral speed of a grinding wheel relative to a working surface is set to 50 to 300 m/sec, a feed stroke speed of the working surface of the grinding wheel in a working direction is set to 50 to 200 m/min, and preferably, a down-feed speed of the working surface of the grinding wheel in a direction orthogonal to the surface of the workpiece is set to 0.05 to 3 mm/min. The grind-machining method of ceramic materials can reduce a grinding force at the time of grinding of ceramic materials and residual defects due to machining, and at the same time, can accomplish high machining efficiency.

Abstract: A silicon nitride sintered body characterized by comprising crystal grains having a linear density of 60 to 120 per 50 .mu.m length as measured in an arbitrary two-dimensional section of the sintered body. The silicon nitride sintered body has a shock compressive elasticity limit (Hugoniot-elastic limit) of 15 GPa or more and is substantially composed of crystal phases of .alpha.-silicon nitride and .beta.'-sialon. The percentages of the .alpha.-silicon nitride and .beta.'-sialon are not more than 30% and not less than 70%, respectively. The silicon nitride sintered body is particularly excellent in mechanical strengths at room temperature as well as in productivity and cost efficiency and is useful for applications as the material of parts where a particularly high impact strength is required, such as a valve train mechanism for automobile parts.

Abstract: Silicon nitride sintered bodies consisting of prismatic crystal grains of Si.sub.3 N.sub.4 and/or sialon, equi-axed crystal grains of Si.sub.3 N.sub.4 and/or sialon, a grain boundary phase existing among the prismatic and equi-axed crystal grains and dispersed particles in the grain boundary phase, in which the prismatic crystal grains have an average grain size of 0.3 .mu.m or less in minor axis and an average grain size of 5 .mu.m or less in major axis, the equi-axed crystal grains have an average grain size of 0.5 .mu.m or less and the dispersed particles have an average size of 0.1 .mu.m or less, the volume of the dispersed particles being 0.05% by volume or more based on the total volume of the rest of the sintered body. The silicon nitride sintered bodies have a strength sufficient for use as structural materials of machine parts or members, with a minimized scattering of the strength as well as high reliability, superior productivity and advantageous production cost.

Abstract: A silicon sintered body comprising a matrix phase consisting of silicon nitride and a grain boundary phase in which the silicon nitride consists of 66 to 99% by volume of .beta.-Si.sub.3 N.sub.4 and/or .beta.'-sialon with the balance being .alpha.-Si.sub.3 N.sub.4 and/or .alpha.'-sialon, the .beta.-Si.sub.3 N.sub.4 and/or .beta.'-sialon consisting of hexagonal rod-like grains having a diameter of 500 nm or less in the minor axis and an aspect ratio 5 to 25, the .alpha.-Si.sub.3 N.sub.4 and/or .alpha.'-sialon consisting of equi-axed grains having an average diameter of 300 nm or less, and titanium compounds are contained within the grains of the matrix phase and in the grain boundary phase. The sintered body is produced by mixing (1) 100 parts by weight of .alpha.-Si.sub.3 N.sub.4 powder, (2) 0.

Abstract: The present invention provides an improved adjusting shim used in a valve train for an internal combustion engine for an automobile. The adjusting shim produced from a base material consisting of a ceramic material containing 80 to 98 wt. % of silicon nitride and/or sialon and has a porosity of not more than 3%, a bending strength of not less than 1.0 GPa and an impact compressive elastic limit (Hugoniot elastic limit) of not less than 15 GPa, wherein the base material is provided on the surface thereof which contacts a cam with a ceramic surface layer having a composition different from that of the base material and a hardness lower than that of the base material. The adjusting shim of the present invention enables a power loss of a valve train to be minimized; the abrasion resistance thereof to be improved; and the fuel economy, the performance and durability of an internal combustion engine to be improved.

Abstract: Described are sintered silicon nitride bodies useful as materials for parts required to have strength, especially excellent impact strength for items such as automobile parts and machine parts. The sintered Si.sub.3 N.sub.4 bodies contain 80-98 wt. % of silicon nitride and have a porosity not higher than 3% and an shock compressive elasticity limit of at least 15 GPa.

Abstract: A silicon nitride sintered body comprising .alpha.-silicon nitride including .alpha.'-sialon and .beta.'-sialon including .beta.-silicon nitride in which the content of the .alpha.-silicon nitride including .alpha.'-sialon in the surface part thereof is less than its content in the inner part thereof. The silicon nitride sintered body is excellent in mechanical strength at ordinary temperature, productivity and cost efficiency.

Abstract: The present invention relates to a silicon nitride sintered body [wherein the composition of Si.sub.3 N.sub.4 -first aid (Y.sub.2 O.sub.3 +MgO)-second aid (at least one of Al.sub.2 O.sub.3 and AlN)] falls within a range defined by lines joining points A, B, C and D in FIG. 1, the crystal phase of the sintered body contains both .alpha.-Si.sub.3 N.sub.4 and .beta.'-sialon, and the relative density is 98% or more. This sintered body is produced by subjecting a green compact of the above-described source to primary sintering in a nitrogen gas atmosphere at 1300 to 1700.degree. C. so that the relative density reaches 96% or more, and the precipitation ratio of the .alpha.-Si.sub.3 N.sub.4 crystal phases to the .beta.'-sialon crystal phase in the sintered body is in the range of from 40:60 to 80:20; and then subjecting the primary sintered body to secondary sintering in a nitrogen gas atmosphere at 1300 to 1700.degree. C. so that the relative density reaches 98% or more.

Abstract: The present invention relates to a silicon nitride sintered body [wherein the composition of Si.sub.3 N.sub.4 -first aid (Y.sub.2 O.sub.3 +MgO)-second aid (at least one of Al.sub.2 O.sub.3 and AlN)] falls within a range defined by lines joining points A, B, C and D in FIG. 1, the crystal phase of the sintered body contains both .alpha.-Si.sub.3 N.sub.4 and .beta.'-sialon, and the relative density is 98% or more. This sintered body is produced by subjecting a green compact of the above-described source to primary sintering in a nitrogen gas atmosphere at 1300.degree. to 1700.degree. C. so that the relative density reaches 96% or more, and the precipitation ratio of the .alpha.-Si.sub.3 N.sub.4 crystal phases to the .beta.'-sialon crystal phase in the sintered body is in the range of from 40:60 to 80:20; and then subjecting the primary sintered body to secondary sintering in a nitrogen gas atmosphere at 1300.degree. to 1700.degree. C. so that the relative density reaches 98% or more.

Abstract: Disclosed is a silicon nitride sintered body produced by subjecting a green compact of a mixed powder composed of 1) a silicon nitride powder having a percentage .alpha. crystallization of 93% or more and a mean grain diameter of 0.7 .mu.m or less and 2) 5 to 15% by weight in total of a first sintering aid selected from among rare earth element, yttrium oxide and lanthanide oxides and a second sintering aid consisting of aluminum oxide or nitride and at least one selected from among oxides and nitrides of Mg, Ca and Li, to primary sintering in a nitrogen gas atmosphere under a pressure of 1.1 atm or less at 1500.degree. to 1700.degree. C.; and subjecting the sintered body to secondary sintering in a nitrogen gas atmosphere under a pressure of 10 atm or more at the primary sintering temperature or below, thereby giving a sintered body wherein the relative density of the sintered body is 99% or more and the precipitation ratio of an .alpha.-Si.sub.3 N.sub.4 (including .beta.