A refrigerant compressor reserves lubricating oil in a sealed container, and accommodates therein an electric component, and a compression component which is driven by the electric component and compresses a refrigerant. At least one of slide members included in the compression component is made of an iron-based material, and an oxide coating film comprising a composition A portion, a composition B portion, and a composition C portion is provided on a slide surface of the iron-based material. The composition A portion is a portion containing diiron trioxide (Fe.sub.2O.sub.3) which is more in quantity than other substances, and is, for example, an outermost portion (160a). The composition B portion is a portion containing triiron tetraoxide (Fe.sub.3O.sub.4) which is more in quantity than other substances and containing a silicon (Si) compound, and is, for example, an intermediate portion (160b). The composition C portion is a portion containing triiron tetraoxide (Fe.sub.3O.sub.4) which is more in quantity than other substances and containing silicon (Si) which is more in quantity than silicon (Si) of the composition B portion, and is, for example, an inner portion (160c).

A refrigerant compressor comprises an electric component; and a compression component which is driven by the electric component and compresses a refrigerant. At least one of slide members included in the compression component is made of an iron-based material. An oxide coating film (150) is provided on a slide surface of the iron-based material, the oxide coating film including a first portion (151), a second portion (152), and/or a third portion (153). The first portion (151) contains at least fine crystals (155). The second portion (152) contains columnar grains (156). The third portion (153) contains layered grains (157).

A method for impregnating a stator of a progressive cavity assembly with nanoparticles. The assembly comprising a stator having an inner core formed on its inner surface, the inner core defining a groove. A primary rotor is disposed within the groove. In operation, the primary rotor is removed from the stator, and a plurality of nanoparticles are distributed throughout the groove. A work rotor is installed within the groove and rotated at a high rate so as to press the nanoparticles into the inner core. The work rotor is removed from the stator and the primary rotor is re-installed into the stator.

A refrigeration cycle apparatus includes a compressor to compress a working fluid to perform a refrigeration cycle. The working fluid contains a hydrofluoroolefin (HFO) having a double bond in a molecular structure thereof. The refrigeration cycle apparatus includes a temperature rise inhibiting unit which inhibits a temperature rise within the refrigeration cycle.

The invention relates to a metallic work-piece (2, 5, 6, 14, 20, 23) for a hydraulic device (1, 15). The workpiece (2, 5, 6, 14, 20, 23) comprises a coating layer (12), characterized in that the coating layer (12) contains Mo, in particular metallic Mo, with a weight fraction of at least 1 %

Disclosed is a coating for reducing or preventing hot-gas oxidation of the piston in an internal combustion engine. Said coating comprises a polysilazane-based polymer.

A steel piston designed to improve thermal efficiency, fuel consumption, and performance of an engine is provided. The piston includes a steel body portion and a thermal barrier layer applied to an upper combustion surface and/or a ring belt to reduce the amount of heat transferred from a combustion chamber to the body portion. The thermal barrier layer has a thermal conductivity which is lower than a thermal conductivity of the steel body portion. The thermal barrier layer typically includes a ceramic material, for example ceria, ceria stabilized zirconia, and/or a mixture of ceria stabilized zirconia and yttria stabilized zirconia in an amount of 90 to 100 wt. %, based on the total weight of the ceramic material. The thermal barrier layer can also have a gradient structure which gradually transitions from 100 wt. % of a metal bond material to 100 wt. % of the ceramic material.

The invention relates to a method for forming a lining on the walls of an inner pipe of a cast aluminium-alloy part, including inserting a cathode into the pipe, circulating an electrolyte solution in said pipe between the cathode and the walls of the pipe forming an anode, and applying a potential difference between the anode and the cathode, the method being characterised in that applying the potential difference between the anode and the cathode includes applying a series of DC voltage pulses to the anode. The invention also relates to a cylinder head in which the exhaust pipes are lined with a lining obtained by implementing said method.

A refrigerant compressor reserves lubricating oil with a viscosity of VG2 to VG100 in a sealed container, and accommodates therein an electric component and a compression component which is driven by the electric component and compresses a refrigerant. The compression component includes at least one slide member comprising a base material 171 made of an iron-based material and an oxide coating film 170 provided on a surface of the base material 171. The oxide coating film 170 includes: a portion containing diiron trioxide (Fe.sub.2O.sub.3), in a region which is closer to an outermost surface of the oxide coating film; and a silicon containing portion containing silicon (Si) which is more in quantity than silicon (Si) of the base material 171, in a region which is closer to the base material 171.

A compressor swash plate includes a base member having a flat plate shape, and a coating layer formed on a surface of the base member and having projections formed in a linear shape, in which the following inequalities are satisfied when a plane part formed on a prism is pressed against the coating layer with a pressure of 30 MPa: 0.01B0.06 and 10S40, where B indicates widths (mm) of surfaces of the projections in contact with the plane part, and S indicates a percentage (%) of a total sum of an area Si of the contact surfaces (a gross area of the surfaces of the projections in contact with the plane part) relative to a reference area (an area of a part of the coating layer against which the plane part is pressed).