A timepiece component includes a base member, a first layer provided at the base member, and a second layer provided at the first layer. The second layer has lower hardness than the first layer.

A method for brazing a first ceramic component and a second metal alloy component, to make a structural or external timepiece element, a zirconia-based ceramic is chosen for the first component and a titanium alloy for the second component, a first recess is made inside the first component, set back from a first surface in a junction area with a second surface of the second component, braze material is deposited on this first surface and inside each recess, the second surface is positioned in alignment with the first surface to form an assembly, this assembly is heated in a controlled atmosphere to above the melting temperature of the braze material, in order to form the braze in the junction area.

The disclosure provides a metal surface layer treating method, a metal assembly and an electronic device. The metal surface layer treating method includes: putting metal into a vacuum chamber, and vacuumizing the vacuum chamber to a first vacuum degree; adding a mixed gas of acetylene, nitrogen and hydrogen into the vacuum chamber; and heating the vacuum chamber to a temperature above an ambient temperature. In response to the temperature in the vacuum chamber reaching a first temperature value above the ambient temperature and a gas pressure of the vacuum chamber reaching a first pressure value, performing glow discharge so that a carbon-nitrogen gradient hardening layer is formed on a surface layer of the metal. The method includes removing part of a carbon layer of the surface layer of the carbon-nitrogen gradient hardening layer.

A watch case (10) comprising a middle (11) to which a crystal (12) and a back (13) are fastened so as to form an internal volume, the watch case (10) including, in the internal volume, an external part component (14) whereon a stack of thin layers (15) comprising a substrate layer (150), a solid-state phase switching layer (151) inserted between a transparent encapsulation layer (152) and a spacing layer (153) separating the phase switching layer (151) from the substrate layer (150) is deposited, the phase switching layer (151) being configured so as to have a refractive index capable of varying under exposure from light rays so as to impart to the stack of thin layers (15) at least two interferential colours.

A watch component includes an austenized ferritic stainless steel including a base including a ferrite phase, a surface layer formed on a surface of the base, the surface layer including an austenized phase, and a mixed layer formed between the base and the surface layer, the mixed layer being a layer in which the ferrite phase and the austenized phase are mixed. In a cross section taken along a depth direction from the surface, a thickness of the mixed layer is 45% or less of a thickness of the surface layer.

A layer of lanthanum boride of stoichiometry LaB.sub.x where 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 LaB.sub.x is deposited by PVD and by cathode sputtering, using a LaB.sub.6 target 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.sub.x. Thus the colour of the treated portions is determined by the material of the substrate.

A watch component includes a metal material obtained by performing a nitrogen absorption treatment on a base material, the base material being a ferritic stainless steel that contains, by mass %, 18 to 22% of Cr, 1.3 to 2.8% of Mo, 0.05 to 0.50% of Nb, less than 0.5% of Ni, less than 0.8% of Mn, less than 0.5% of Si, less than 0.10% of P, less than 0.05% of S, less than 0.05% of N, and less than 0.05% of C, with a remainder thereof being composed of Fe and an unavoidable impurity.

A watch component comprising an austenitic ferritic stainless steel. The austenitic ferritic stainless steel includes a base portion composed of a ferrite phase, a surface layer composed of an austenitic phase, and a mixed layer formed between the base portion and the surface layer, wherein the mixed layer is composed of the ferrite phase and the austenitic phase. The surface layer contains 1.0 to 1.6 mass % of nitrogen, in which the surface layer has, at a surface of the surface layer, an oxide film having a thickness of 2.5 nm or greater, as calculated in terms of oxygen profiles in AES analysis.

A method for depositing a rare material in a thin layer at the surface of an horological or jewellery external part includes providing a rough part of rare material, shaping the rough part of rare material so that it is adapted to be used as a target part for a PVD method, depositing material of the target part at the surface of a substrate consisting of an horological or jewellery eternal part by a PVD method so as to cover the external part.

The invention relates to a method for decorating a timepiece component comprising: a) a step of preparation of the timepiece component optionally comprising a first step of depositing a first material on the timepiece component to form a first sub-layer, b) a second step of depositing a second material on the timepiece component obtained in step a) to form a second sub-layer, c) a colouring step comprising the deposition of a third coloured material on the timepiece component obtained in step b) to form a coloured external decorative layer,

According to the invention, at least step b) and step c) are achieved by a physical vapour deposition method.