The Swatch Group Research and Development Ltd

Christian Manasterski

Cedric Faure

Vladislav Spassov

Marion Gstalter

Simon Springer

Cédric Faure

Gerard Rossier

Gérard Rossier

A layer of lanthanum boride of stoichiometry LaBwhere x is between 9 and 12 is deposited on substrate, for example a stainless steel watch dial, and subsequently treated with a laser, such that the portion(s) of the layer treated with the laser change colour according to the laser power. This produces multicoloured surfaces having high resistance to corrosion and abrasion. The layer of LaBis deposited by PVD and by cathode sputtering, using a LaBtarget of purple-violet colour, such that the colour of the deposited layer differs from the colour of the target. The laser treatment at specific powers changes the stoichiometry of the layer in the treatment portions, such that the colour of these portions changes according to the stoichiometry obtained. At higher powers, the laser will remove the layer of LaB. Thus the colour of the treated portions is determined by the material of the substrate.

Decorative object

A substrate includes a final silver-plated surface protected against silver tarnishing by a protective coat having a thickness between 1 nm and 200 nm, the protective coat includes a first coat of AlOdeposited on said final silver-plated surface and having a thickness between 0.5 nm and 100 nm, and on the first coat of AlO, a second coat of TiOhaving a thickness between 0.5 nm and 100 nm, the substrate including a coat of a silver and copper alloy comprising between 0.1% and 10% by weight of copper with respect to the total weight of the alloy, forming said final silver-plated surface, said coat of a silver and copper alloy having a thickness between 1000 nm and 3000 nm. Embodiments also relate to a method for manufacturing such a substrate.

Substrate comprising a silver-plated surface protected against silver tarnishing and method for manufacturing such a substrate

Method for manufacturing a decorative surface

A method is described for protecting a silver surface against tarnishing. This involves depositing a layer of a silver-copper alloy on a substrate, which may be a silver substrate. The alloy comprises between 0.1 wt % and 10 wt % of copper relative to the total weight of the alloy. At least one layer of a metal oxide or a nitride having a thickness in a range of 1 nm to 200 nm is deposited on the alloy to protect against tarnishing. The presence of copper in the silver-copper alloy enhances the alloy's adhesion without altering the silver color.

Method for enhancing the adhesion of a layer for the protection of silver against tarnishing on a substrate comprising a silver surface

The invention relates to a method for decorating a timepiece component comprising: According to the invention, at least step b) and step c) are achieved by a physical vapour deposition method.

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Colombier, Switzerland

Christian Manasterski