A silicon nitride sintered body includes at least one black portion with a major axis of 10 μm or more in a field of view with a unit area of 5 mm×5 mm, when observing an arbitrary cross-section of the silicon nitride sintered body using a metallurgical microscope. A major axis of the black portion is Preferably 500 μm or less. The number of the black portion within the field of view with a unit area of 5 mm×5 mm is preferably 2 or more and 10 or less. A segregation portion of Fe is preferably included in the black portion.

A bearing including a backing formed of a steel material, a lining formed of aluminum or an aluminum alloy, and a diffusion barrier layer disposed between the backing and the lining is provided. The diffusion barrier layer is formed of nickel or a nickel alloy and has a thickness ranging from 1 micron to 100 microns. The bearing is typically formed by cladding the lining or plating the steel backing with the diffusion barrier layer, bonding the lining and the backing with the diffusion barrier layer between, heating to a temperature of at least 400° C., and forming the bearing into a shape after or before the heating step.

A bearing assembly includes a roller bearing unit, an inner race and an outer race. The roller bearing unit is formed of polycrystalline super-hard material having a mean mass density of at most 4.5 g/cm.sup.3 and a volume-weighted arithmetic mean thermal conductivity of at least 100 W/m.Math.K.

A bearing component, such as a bearing roller or a bearing ring, has an exterior surface and includes at least one interior region made of a recycled material which region is spaced from and does not form any part of the exterior surface. The recycled material and the unrecycled material may each include silicon nitride and/or sialon and/or silicon carbide and/or a ceramic material. Also a method of forming the component.

Inventive manufacture of CrB.sub.2—Al.sub.2O.sub.3 composites is based on pressureless sintering. According to typical inventive practice, CrB.sub.2 powder and Al.sub.2O.sub.3 powder are mixed together in selected volumetric proportions so that the volume of the CrB.sub.2 does not exceed 50% of the overall volume of the CrB.sub.2—Al.sub.2O.sub.3 mixture. The CrB.sub.2—Al.sub.2O.sub.3 mixture is shaped into a green body. The green body is pressureless sintered in a non-oxidizing atmosphere at a firing temperature in the approximate range between 1600° C. and 2050° C. The present invention succeeds in preparing, via pressureless sintering, a proportionality-associated range of compositions in the CrB.sub.2—Al.sub.2O.sub.3 system, which is a potentially “advanced” ceramic system. A typical inventively fabricated CrB.sub.2—Al.sub.2O.sub.3 composite is inventively configured in a complex shape, and has “advanced” material (e.g., mechanical) properties that are favorable for a contemplated application. Inventive manufacture of ceramic-ceramic composites is thus dually attributed, and uncommonly so, with complex shape-ability and advanced capability.

A cage (5) for separating rolling bodies (2) for a bearing (1), particularly for a timepiece bearing, the cage having first openings (50) for receiving rolling bodies and at least one first contact zone (56) intended to come into contact with a bearing ring and having at least one first hollow formation (52).

Provided are a sintered ceramic and a ceramic sphere which are inhibited from suffering surface peeling due to fatigue resulting from repetitions of loading and can attain an improvement in dimensional accuracy when subjected to surface processing and which have excellent wear resistance and durability.

Embodiments disclosed herein relate to bearing apparatuses including a bearing assembly having a continuous superhard bearing element including a continuous superhard bearing surface and a tilting pad bearing assembly. The disclosed bearing apparatuses may be employed in pumps, turbines or other mechanical systems. In an embodiment, the bearing apparatus includes a first and second bearing assembly. The first bearing assembly includes a first support ring and a plurality of tilting pads. Each tilting pad is tilted and/or tiltably secured relative to the first support ring. The second bearing assembly includes a continuous superhard bearing element. The continuous superhard bearing element includes a continuous superhard bearing surface facing the plurality of tilting pads and exhibits a maximum lateral width greater than about 2 inches.

A bearing assembly includes a roller bearing unit, an inner race and an outer race. The roller bearing unit is formed of polycrystalline super-hard material having a mean mass density of at most 4.5 g/cm.sup.3 and a volume-weighted arithmetic mean thermal conductivity of at least 100 W/m.Math.K.

Provided is sliding components capable of stably obtaining a low-friction effect even in a non-lubricated environment. Sliding components and have sliding surfaces and performing relative sliding. A carbon film in which a polymer structure is dispersed is formed on the sliding surface of the sliding component. The proportion of the polymer structure dispersed in the carbon film is such that an extinction coefficient of 0.2 or less and a refractive index of 1.5 to 2.0 are satisfied in a wavelength range of 550 nm of spectroscopic ellipsometry.