METHOD OF DEPOSITING A HARD COATING OF A METAL, DEPOSITION TARGET FOR SUCH A METHOD AND PIECE OF JEWELLERY COMPRISING SUCH A COATING

摘要

The invention relates to a process of deposition of a coating of a gold compound on a solid substrate. In a vacuum chamber (1), the substrate is fixed on a first substrate electrode (2). A composite target (5) essentially consists of gold and at least one of the metal compounds, such as nitride, carbide and boride of the metals of group IV b of the periodic classification of elements and tantalum. A high-purity argon atmosphere at pressure ranging between 4x10-4 and 3x10-2 Torr is then established in the chamber. The deposition of the coating is then carried out by ionic deposition or evaporation in vapor phase at a given rate. The invention may find application to coat articles of jewelry or of watch cases.