Pulse-managed plasma method for coating on internal surfaces of workpieces

Abstract

An article has a cavity defined by an inner surface, the cavity having a size such that a largest sphere placeable in the cavity has a diameter of less than 7 cm and a smallest sphere placeable in the cavity has a diameter of 0.5 mm; and a hard coating on the inner surface, the hard coating having a hardness between 18 to 100 GPa, the hard coating distributed on the inner surface such that a ratio of a coating thickness at a first region of the hard coating to that at a second region of the hard coating ranges from 0.75 to 1.33.

Dependencies are inferred from the claim text.