Method for manufacturing a part by alloying a precious metal with boron, the precious metal being selected from the group formed by gold, silver, platinum, palladium, ruthenium, rhodium and iridium, this method comprising the steps of: - providing at least one quantity of precious metal reduced to powder form; - providing a quantity of a nano-structured micrometric powder formed by aggregates of particles, these aggregates which constitute the nano-structured micrometric powder having dimensions within the micrometric range, these aggregates being themselves constituted of particles containing, at least in part, boron, and which have at least one geometrical value within the nanometric range responsible for the reactivity of the nano-structured micrometric powder; - mixing the precious metal powder with the boron-containing nano-structured micrometric powder and compacting this mixture of powders by applying a uniaxial pressure; - subjecting the mixture of precious metal powder and nano-structured micrometric powder to a spark plasma sintering or flash sintering treatment at a pressure that lies in the range 0.5 GPa to 10 GPa, or to a hot isostatic pressing treatment at a pressure that lies in the range 80 bar to 2,200 bar, the treatment being carried out at a temperature that lies in the range 400°C to 2,100°C in order to obtain at least one ingot of an alloy containing precious metal and boron, and - machining the precious metal- and boron-containing alloy ingot to obtain the desired part, or - reducing the precious metal- and boron-containing alloy ingot to powder form by a micronisation treatment, and obtaining the desired part by treating the powder resulting from the micronisation treatment. - providing at least one quantity of precious metal reduced to powder form; - providing a quantity of a nano-structured micrometric powder formed by aggregates of particles, these aggregates which constitute the nano-structured micrometric powder having dimensions within the micrometric range, these aggregates being themselves constituted of particles containing, at least in part, boron, and which have at least one geometrical value within the nanometric range responsible for the reactivity of the nano-structured micrometric powder; - mixing the precious metal powder with the boron-containing nano-structured micrometric powder and compacting this mixture of powders by applying a uniaxial pressure; - subjecting the mixture of precious metal powder and nano-structured micrometric powder to a spark plasma sintering or flash sintering treatment at a pressure that lies in the range 0.5 GPa to 10 GPa, or to a hot isostatic pressing treatment at a pressure that lies in the range 80 bar to 2,200 bar, the treatment being carried out at a temperature that lies in the range 400°C to 2,100°C in order to obtain at least one ingot of an alloy containing precious metal and boron, and - machining the precious metal- and boron-containing alloy ingot to obtain the desired part, or - reducing the precious metal- and boron-containing alloy ingot to powder form by a micronisation treatment, and obtaining the desired part by treating the powder resulting from the micronisation treatment.