GOLD ALLOY WITH IMPROVED HARDNESS

摘要

The invention relates to a gold alloy. It comprises at least 75% gold, from 0.5% to 2.1% aluminium capable of forming precipitates with the gold, an additional metal capable of favouring a stable face-centred cubic structure, and capable of increasing the solubility of the aluminium in the gold, and one such precipitate selected in order to obtain a hardness of greater than 250 HV. The selected precipitate of aluminium with the gold is the precipitate of aluminium and of gold Al2Au5; it comprises from 0.5% to 2.1% aluminium, and a supplement of additional metal comprising a majority of silver. The process for obtaining this alloy regulates a controlled growth of this precipitate during a structural tempering consecutive to a dilution and to a quenching. The invention relates to the use of the precipitate of aluminium and of gold Al2Au5 for the hardening of a gold alloy. The invention relates to a time piece or jewellery part comprising a component made in this alloy.