A jewelry item includes a thin piece member formed from a gold alloy containing gold (Au) as a first metal element and a second metal element other than gold (Au), a frame member including a third metal element other than the first metal element and the second metal element and a fourth metal element as a metal for an alloy of the third metal, forming a bond with and surrounding a peripheral edge of the thin piece member, and a compound layer containing the first metal element, the second metal element, the third metal element and the fourth metal element is interposed between the thin piece member and the frame member.

A timepiece part according to the invention includes: a substrate; and a first coating configured from a material containing cobalt as a primary component, and 26 mass % to 30 mass % of Cr, and 5 mass % to 7 mass % of Mo. The first coating has a surface with a percentage surface area increase of 0% to 1.2% as measured by atomic force microscopy against a reference flat surface.

Sintered product having a chemical analysis such that, in percentages by mass based on the oxides, ZrO2 partially stabilised with CeO2 and Y2O3: remainder up to 100%, Al2O3: >10% and <19%of an additive selected from CaO, the oxides of manganese, ZnO, the oxides of praseodymium, SrO, the oxides of copper, Nd2O3, BaO, the oxides of iron, and mixtures thereof: 0.2-6%, impurities: <2%, CeO2 and Y2O3 being present in quantities such that, in molar percent based on the sum of ZrO2, CeO2 and Y2O3, CeO2: 2.5 mol % and <5.5 mol %, and Y2O3: 0.5-2 mol %.

A timepiece or piece of jewellery includes at least one component made of a palladium-based alloy. The palladium-based alloy consists of, expressed in weight percentage: from 50% to 55% of palladium, from 45% to 50% of rhodium, more than 0% and less than or equal to 5% of silver, and more than or equal to 0% and less than or equal to 5% of at least one element R selected from the group consisting of iridium, ruthenium, platinum, titanium, zirconium, and rhenium. Said at least one component made of the palladium-based alloy has colorimetric values according to the L*a*ab chromatic model (CIE 1976) such that L* is comprised between 88 and 90, a* is lower than or equal to 0.8 and b* is lower than or equal to 3.

An external component for timepieces or pieces of jewelry, made of a light precious alloy containing titanium and palladium, according to the atomic formula Ti.sub.aPd.sub.bM.sub.cT.sub.d, where a, b, c, d are atomic fractions of the total, such that a+b+c+d=1. a is 0.44 to 0.55, b is 0.30 to 0.45, c is 0.04 to 0.24, and d is 0.001 to 0.03. The alloy includes at most two metals M, taken from among Nb, V, Fe, Co, Au, Pt. Each metal trace T has an atomic percentage of less than 3.00% of the total alloy, from among Nb, V, Mo, Ta, W, Fe, Co, Ni, Ru, Rh, Ir, Au, Pt, Cr, Mn, Cu, Zn, Ag, Al, B, Si, Ge, Sn, Sb, and In. The alloy contains at least 0.05% of boron, and contains at least 50% by mass of palladium.

The present invention is directed to a jewelry element which includes two layersa cladding layer and a substrate layer, each layer being its own alloy. The cladding layer and the substrate layer each include a base metal such as silver or gold at the same percentages so that the resulting jewelry element can be labeled in accordance with one or more industry-wide requirements. The cladding layer is further enhanced by introduction of a metal providing additional hardness when included in the alloy. By limiting the hardness metal or metals to being deposed only in the cladding layer, less of the hardness metal need be used, thereby reducing cost yet retaining the requisite hardness characteristic. Each of the alloys may further contain other metals for any of a number of reasons, including but not limited to, tarnish resistance.

The metal matrix composite material for a horological component comprises a metal alloy based on gold, with at least 75% by weight of gold, or based on platinum, with at least 95% by weight of platinum, or based on palladium, with at least 95% by weight of palladium, the composite material further including between 0.1% and 2% by weight, or even between 0.5% and 2% by weight, or even between 0.5% and 1.5% by weight, or even between 0.5% and 1.25% by weight, or even between 0.5% and 1% by weight, of at least one hardening element, and a reinforcing material, in a proportion by mass of between 1% and 10%, or even between 1% and 5%, the reinforcing material including ceramic particles.

Silicone is placed between an upper die and an injection-pressing rubber-lid upper die, and the silicone injection passage is pressurized by the injection-pressing rubber-lid upper die. With this, the silicone is caused to flow into an injection port through the silicone injection passage. Then, sequentially through the injection port and the disc silicone-flow passage, the silicone is caused to flow toward an inner periphery of a silicone injection space. Further, the silicone flows between both circumferential sides of the silicone-flow deflection region. In this way, the silicone flows in a peculiar manner in conformity with a shape of the silicone-flow deflection region.

A composite material combininga precious metal or an alloy containing a precious metaland a boron-based ceramic having a melting point greater than that of said precious metal and a density at most equal to 4 g/cm3.

A method of manufacturing yellow, red or white gold jewelry items layer by layer by selective laser melting (SLM) of a 18K, 14K, 10K or 9K gold powder alloy. The alloy comprises: (A) 37.5% to 38.5% by weight or 41.7% to 42.5% by weight or 58.5% to 59.5% by weight or 75% to 76% by weight of gold; and (D) 0.01% to 5% by weight, preferably 0.01% to 3% by weight of at least one metalloid, which may be germanium, silicon, boron, tellurium, phosphorous and selenium.