A metal matrix self-lubricating composite and a manufacturing method therefor. The metal matrix self-lubricating composite comprises a metal matrix and a mixture layer compounded on a surface of the metal matrix, the mixed layer comprising a copper alloy and a self-lubricating material. The method for manufacturing the metal matrix self-lubricating composite comprises the following steps: a) sintering copper alloy powder on a surface of a metal matrix to form a copper alloy layer on the surface of the metal matrix; b) blade-coating or dip-coating a lubricating material on a surface of the copper alloy layer, and performing vacuumization to obtain a metal plate, and drying the metal plate; c) repeating step b) for multiple times; and d) sintering the metal plate obtained in step c) to obtain the metal matrix self-lubricating composite. In the present invention, a vacuumization mode is used and vacuumization operations are repeated, so that a dense mixture layer on which a self-lubricating material is dispersed on a copper alloy is formed, and the metal matrix self-lubricating composite has good lubricity and abrasion resistance.

A green compact according to the present invention is a green compact, which is obtained by compaction-molding raw material powder containing metal powder as a main raw material, the green compact including an oxide film formed between particles of the raw material powder forming the green compact, the oxide film binding the particles of the raw material powder to each other, in which the metal powder to toe used includes metal powder showing a circularity R at a cumulative frequency of 80% of 0.75 or more, the circularity R being expressed by Equation (1), where S represents a two-dimensional projected area of the metal powder and L represents a two-dimensional projected circumferential length of the metal powder.

[00001]$\begin{array}{cc}R=4.Math.\pi \times \frac{S}{L^2}& \left(1\right)\end{array}$

An automotive shaft includes a journal having a crest-to-crest contact surface area defined by and between undercut regions of the shaft, an entirety of the crest-to-crest contact surface area being laser hardened to a depth no greater than 1 mm to form a layer that does not contain unhardened portions.

Bearing component providing unaffected material that has a surface, which has been subjected to a hard machining process during where the temperature of the surface did not exceed the austenitizing temperature of the unaffected material. The surface of the bearing component includes a white layer formed during the hard machining process. The white layer has a nano-crystalline microstructure that includes grains having a maximum grain size up to 500 nm. The white layer is located directly adjacent to the unaffected material of the bearing component, where no dark layer is formed during the hard machining process.

This disclosure relates to a manufacture method of a bushing, a bushing and an excavator to alleviate the problems of insufficient lubricity and wear resistance of the bushing. The bushing includes an inner ring and an outer ring. The manufacture method of the bushing includes the following steps: grinding a first mixed powder containing Fe, Al, Ti, Cr and V, nitriding the ground first mixed powder to form a nitrogen-rich stable compound powder, and then carrying out molding by pressing and sintering the nitrogen-rich stable compound powder to form the outer ring; grinding a second mixed powder containing Fe and Mo, sulfurizing the ground second mixed powder to form a sulfurized powder containing FeS and MoS.sub.2, and carrying out molding by pressing the sulfurized powder to form the inner ring; and placing the inner ring in the outer ring and carrying out sintering to obtain the bushing.

A sliding member includes a metallic substrate, a porous layer formed on a surface of the metallic substrate, and a sliding layer that covers the porous layer. The porous layer is made of a metal itself or an alloy composition. The sliding layer is made of a lead-free resin composition. The resin composition consists of a pitch-based carbon fiber and a fluororesin, and assuming weight of the resin composition as 100, more than 10 weight % and 35 weight % or less of the pitch-based carbon fiber is contained.

Among other things, a bearing assembly comprising a hybrid coating is provided. A bearing assembly may comprise a substrate having a surface and a hybrid wear resistant coating over the surface of the substrate. In an example, the substrate may be an inner radial bearing and/or and outer radial bearing within a bearing assembly. The hybrid wear resistant coating may comprise a high wear resistant coating and a low wear resistant coating. The high wear resistant coating may comprise a wear resistant matrix over the surface and a set of wear resistant elements within the wear resistant matrix. In an example, wear elements within the set of wear elements may comprise tungsten carbide. The low wear resistant coating may be over a low wear area of the surface. In an example, the low wear resistant coating may be positioned between the first high wear resistant coating and a second high wear resistant coating.

Methods for manufacturing bearings and wear resistant surfaces usable in various downhole tools are described herein. A housing is provided. A laser configured for insertion into the housing, such as an inner diameter laser, is used to connect a fusible material to the inner surface of the housing or an insert disposed therein to form a hard facing layer on the inner surface. Simultaneously or independently, the laser can be used to connect the fusible material to the outer surface of a mandrel within the housing to form a second hard facing layer. The present methods thereby produce durable radial bearings having extended operational life, which can be produced within a bearing housing, or externally for transport and installation in existing bearing housings.

Methods for manufacturing bearings and wear resistant surfaces usable in various downhole tools are described herein. A housing is provided. A laser configured for insertion into the housing, such as an inner diameter laser, is used to connect a fusible material to the inner surface of the housing or an insert disposed therein to form a hard facing layer on the inner surface. Simultaneously or independently, the laser can be used to connect the fusible material to the outer surface of a mandrel within the housing to form a second hard facing layer. The present methods thereby produce durable radial bearings having extended operational life, which can be produced within a bearing housing, or externally for transport and installation in existing bearing housings.

A shaft supporting unit 15A supports a shaft of a pivoting body with capacity of pivot movement. A lower block 58A has a lower recess with a semicircular column shape, and is configured to support the shaft from beneath. A lower bush 59 has a semi-cylindrical shape, is located in the lower recess, and is configured to slide the shaft on it. The shaft supporting unit 15A does not abut an upper side of the shaft when the pivoting body pivots. An upper block 56A is configured to cover above the shaft, and has an upper recess with a predetermined gap between it and the shaft.