A gear pump for a gas turbine engine including a first gear having a plurality of gear teeth supported for rotation on a gear shaft relative to a second gear, wherein the gear teeth are formed from a steel base material and surfaces of the gear teeth are coated with a cavitation resistant coating material, and a journal bearing for carrying a gear shaft load through a fluid film pressure between a surface of the gear shaft and a surface of the journal bearing, wherein at least a portion of the journal bearing is formed from a cavitation resistant base material.

A fluid gear pump gear arranged to rotate about a first axis. The fluid gear pump gear includes a concentrically disposed first hub portion and a plurality of first teeth radially projecting and circumferentially spaced about the first hub portion, the first hub portion and the first teeth being coated with a vapor-deposited of cavitation resistant coating. The gear also includes a first shaft on which the first hub portion is carried.

A compressor of an embodiment includes a compression mechanism part that compresses a refrigerant in a sealed container. The compression mechanism part includes Cr and includes a first member and a second member which slidingly move relative to each other. The first member has a chromium layer and a nitride layer formed on a base member surface in this order. The nitride layer includes CrN and TiN. Carbide is deposited on a surface of the second member.

A compressor of an embodiment includes a sealed container and a compression mechanism part configured to compress a refrigerant within the sealed container. The refrigerant is an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant. The compression mechanism part contains chromium. The compression mechanism part includes a first member and a second member. The first member and the second member slide relative to each other. A blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member. The titanium nitride in the blend layer is distributed such that a concentration of the titanium nitride increases and decreases regularly in a thickness direction of the blend layer. Carbide is precipitated on a surface of the second member.