Abstract: A gold alloy including, by weight, between 73% and 77% gold, between 20% and 24.5% silver, palladium and/or platinum with a total percentage for these two elements between 0.5% and 5%. With the addition of palladium and/or platinum, this alloy has an enhanced tarnishing resistance while having a green tint.

Abstract: A platinum alloy consisting, by weight, of the following elements: 95.00 to 96.00% of Pt, 1.00 to 4.95% of Ru, 0.05 to 2.00% of Ge, 0 to 2.00% of Au, any impurities with a total content 0.50%.

Abstract: A platinum alloy consisting, by weight, of the following elements: 95.00 to 96.00% of Pt, 1.00 to 4.95% of Ru, 0.05 to 2.00% of Ge, 0 to 2.00% of Au, any impurities with a total content?0.50%.

Abstract: A zinc-free gold alloy containing by weight between 37% and 38.5% of gold, between 4 and 32% of palladium and/or silver, between 25% and 54% of copper and between 0% and 10% of gallium. A timepiece or piece of jewellery or gemstone jewellery made of this alloy.

Abstract: The invention concerns a method for heat treatment of an austenitic steel of the High Nitrogen Steel or austenitic HNS type, or of an austenitic steel of the High Interstitial Steel or austenitic HIS type, said austenitic HNS or austenitic HIS containing precipitates of nitrides, carbides or carbonitrides of chromium and/or of molybdenum, this method comprising the step which consists, after machining the austenitic HNS or austenitic HIS containing the precipitates, in redissolving the precipitates by bringing the austenitic HNS or austenitic HIS to its austenitizing temperature, then cooling the austenitic HNS or austenitic HIS sufficiently rapidly to avoid the re-formation of precipitates. The invention also concerns different heat treatment methods allowing chromium and/or molybdenum nitride, carbide or carbonitride type precipitates to appear in an austenitic HNS or austenitic HIS.

Abstract: A zinc-free gold alloy containing by weight between 37% and 38.5% of gold, between 4 and 32% of palladium and/or silver, between 25% and 54% of copper and between 0% and 10% of gallium. A timepiece or piece of jewellery or gemstone jewellery made of this alloy.

Abstract: The invention relates to a timepiece component (1) comprising at least one portion (3) machined by chip removal. Said portion (3) is made of a non-magnetic copper alloy in order to limit its sensitivity to magnetic fields, said copper alloy containing between 10 wt % and 20 wt % of Ni, between 6 wt % and 12 wt % of Sn, X wt % of additional elements, wherein X is comprised between 0 and 5, and the remainder is Cu. The invention concerns the field of timepiece movements.

Abstract: The invention relates to a timepiece component (1) comprising at least one portion (3) machined by chip removal. Said portion (3) is made of a non-magnetic copper alloy in order to limit its sensitivity to magnetic fields, said copper alloy containing between 10 wt % and 20 wt % of Ni, between 6 wt % and 12 wt % of Sn, X wt % of additional elements, wherein X is comprised between 0 and 5, and the remainder is Cu. The invention concerns the field of timepiece movements.

Abstract: The invention concerns a method for heat treatment of an austenitic steel of the High Nitrogen Steel or austenitic HNS type, or of an austenitic steel of the High Interstitial Steel or austenitic HIS type, said austenitic HNS or austenitic HIS containing precipitates of nitrides, carbides or carbonitrides of chromium and/or of molybdenum, this method comprising the step which consists, after machining the austenitic HNS or austenitic HIS containing the precipitates, in redissolving the precipitates by bringing the austenitic HNS or austenitic HIS to its austenitizing temperature, then cooling the austenitic HNS or austenitic HIS sufficiently rapidly to avoid the re-formation of precipitates. The invention also concerns different heat treatment methods allowing chromium and/or molybdenum nitride, carbide or carbonitride type precipitates to appear in an austenitic HNS or austenitic HIS.