Abstract: A method is for manufacturing an ornamental part, for example a watch, jewellery or telephone part, in particular a watch crown. The part includes, at least partially, a hard material with a Vickers hardness exceeding 1,000 HV. The method includes the following main steps: producing a precursor from a mixture of at least one powder material with a binder, producing an insert made of a polymer material, the insert having, at least partially, a negative shape of that desired for at least one portion of the part, overmoulding the precursor onto the insert made of a polymer material by injection into a mould to form a green body, and sintering the green body to form a body of the future part from the hard material.

Abstract: A binder for an injection moulding composition including: from 40 to 55 volume percent of a polymeric base, from 35 to 45 volume percent of a mixture of waxes or a mixture of wax and palm oil, and at least 5 volume percent of at least one surfactant, wherein the polymeric base is formed of copolymers of ethylene and methacrylic or acrylic acid, copolymers of ethylene and propylene and/or maleic anhydride-grafted polypropylene, and polymers soluble in isopropyl alcohol, propyl alcohol and/or turpentine, and chosen from the group including a cellulose acetate butyrate, a polyvinyl butyral and a copolyamide, the respective quantities of the binder components being such that their sum is equal to 100 volume percent of the binder.

Abstract: A support frame for a sintering step of a method for producing a part, in particular for watchmaking, from a green body having an initial shape, the body shrinking from the initial shape to a final shape during the sintering step, the support frame having at least one face for supporting the body during the sintering step, wherein the geometry of the supporting face is in relief and configured to support the body from its initial shape into its final shape, so that it retains its shape and proportions in line with a shrinkage coefficient related to the sintering operation. The disclosure further relates to a sintering method using this support frame.

Abstract: A mixer for ceramic feedstock pellets includes a tank, a mixing device within the tank, and a heat exchanger including a cooler for cooling of the content of this tank. A controller controls the heat exchanger which includes a heater arranged to heat the content of this tank to a temperature comprised between a lower temperature (TINF) and a higher temperature (TSUP) stored in a memory for a specific mixture. The heater exchanges energy with a heat exchanger and mixing temperature maintenance circuit, external to this tank. The thermal inertia of this circuit is higher than that of this fully loaded tank.

Abstract: A binder for an injection moulding composition includes: from 35 to 54% by volume of a polymeric base, from 40 to 55% by volume of a mixture of waxes, and approximately 10% by volume of a surfactant, wherein the polymeric base contains copolymers of ethylene and methacrylic or acrylic acid, or copolymers of ethylene and vinyl acetate, or copolymers of ethylene including maleic anhydride or a mixture of these copolymers, as well as polyethylene, polypropylene and acrylic resin.

Abstract: A binder for an injection moulding composition including: from 40 to 55 volume percent of a polymeric base, from 35 to 45 volume percent of a mixture of waxes or a mixture of wax and palm oil, and at least 5 volume percent of at least one surfactant, wherein the polymeric base is formed of copolymers of ethylene and methacrylic or acrylic acid, copolymers of ethylene and propylene and/or maleic anhydride-grafted polypropylene, and polymers soluble in isopropyl alcohol, propyl alcohol and/or turpentine, and chosen from the group including a cellulose acetate butyrate, a polyvinyl butyral and a copolyamide, the respective quantities of the binder components being such that their sum is equal to 100 volume percent of the binder.

Abstract: A binder for an injection moulding composition includes: from 35 to 54% by volume of a polymeric base, from 40 to 55% by volume of a mixture of waxes, and approximately 10% by volume of a surfactant, wherein the polymeric base contains copolymers of ethylene and methacrylic or acrylic acid, or copolymers of ethylene and vinyl acetate, or copolymers of ethylene including maleic anhydride or a mixture of these copolymers, as well as polyethylene, polypropylene and acrylic resin.

Abstract: A process for the production of a grey zirconia-based article wherein a first mixture includes a zirconia powder forming the base constituent, 4% to 15% by weight of at least one stabilizer selected from among the group of oxides including yttrium oxide, magnesium oxide and calcium oxide alone or in combination, 0.1% to 1% by weight of a vanadium oxide powder (V2O5), 0.1% to 1% by weight of a chromium oxide powder (Cr2O3) and 0.1% to 1% by weight of a silicon oxide powder (SiO2); making a second mixture including the first mixture and a binder; making a granulated mixture by conducting a granulation of the second mixture; forming a blank by giving this second granulated mixture the shape of the desired article; sintering the blank in air for at least thirty minutes at a temperature in the range of between 1250° and 1550° C.

Abstract: The invention also concerns a binder for an injection molding composition including: from 35 to 54% by volume of a polymeric base, from 40 to 55% by volume of a mixture of waxes, and approximately 10% by volume of a surfactant, wherein the polymeric base contains copolymers of ethylene and methacrylic or acrylic acid, or copolymers of ethylene and vinyl acetate, or copolymers of ethylene including maleic anhydride or a mixture of these copolymers, as well as polyethylene, polypropylene and acrylic resin.

Abstract: A mixer for ceramic feedstock pellets with a tank, a mixing shaft, and a heat exchanger including a cooler for the cooling of the content of this tank is provided. A controller controls the heat exchanger which includes a heater arranged to heat the content of this tank to a temperature comprised between a lower temperature (TINF) and a higher temperature (TSUP) stored in a memory for a specific mixture, and the heater exchanges energy with a heat exchange and mixing temperature maintenance circuit, external to this tank, and wherein the thermal inertia of this circuit is higher than that of this fully loaded tank. The invention also concerns a method for mixing raw material for powder metallurgy, implementing a specific injection molding composition and a specific binder.

Abstract: Mixer for ceramic feedstock pellets with a tank, a mixing means, and heat exchange means including cooling means for the cooling of the content of this tank. Control means control the heat exchange means which include heating means arranged to heat the content of this tank to a temperature comprised between a lower temperature (TINF) and a higher temperature (TSUP) stored in a memory for a specific mixture, and the heating means exchange energy with a heat exchange and mixing temperature maintenance circuit, external to this tank, and wherein the thermal inertia of this circuit is higher than that of this fully loaded tank. The invention also concerns a method for mixing raw material for powder metallurgy, implementing a specific injection moulding composition and a specific binder.

Abstract: A process for the production of a grey zirconia-based article wherein a first mixture includes a zirconia powder forming the base constituent, 4% to 15% by weight of at least one stabiliser selected from among the group of oxides including yttrium oxide, magnesium oxide and calcium oxide alone or in combination, 0.1% to 1% by weight of a vanadium oxide powder (V2O5), 0.1% to 1% by weight of a chromium oxide powder (Cr2O3) and 0.1% to 1% by weight of a silicon oxide powder (SiO2); making a second mixture including the first mixture and a binder; making a granulated mixture by conducting a granulation of the second mixture; forming a blank by giving this second granulated mixture the shape of the desired article; sintering the blank in air for at least thirty minutes at a temperature in the range of between 1250° and 1550° C.

Abstract: The invention also concerns a binder for an injection moulding composition including: from 35 to 54% by volume of a polymeric base, from 40 to 55% by volume of a mixture of waxes, and approximately 10% by volume of a surfactant, wherein the polymeric base contains copolymers of ethylene and methacrylic or acrylic acid, or copolymers of ethylene and vinyl acetate, or copolymers of ethylene including maleic anhydride or a mixture of these copolymers, as well as polyethylene, polypropylene and acrylic resin.

Abstract: Mixer for ceramic feedstock pellets with a tank, a mixing means, and heat exchange means including cooling means for the cooling of the content of this tank. Control means control the heat exchange means which include heating means arranged to heat the content of this tank to a temperature comprised between a lower temperature (TINF) and a higher temperature (TSUP) stored in a memory for a specific mixture, and the heating means exchange energy with a heat exchange and mixing temperature maintenance circuit, external to this tank, and wherein the thermal inertia of this circuit is higher than that of this fully loaded tank. The invention also concerns a method for mixing raw material for powder metallurgy, implementing a specific injection moulding composition and a specific binder.