Outer part of a casing for a watch, where outer part is made of quasi-beta titanium alloy that is subjected to a hardening treatment comprising heating the alloy at a specified value, quenching and then tempering to obtain a hardness

摘要

The outer part of a casing for watch, is claimed. The outer part is made of quasi-beta titanium alloy, which is subjected to a hardening treatment comprising heating the titanium alloy at a temperature of 760[deg] C+- 5[deg] C below beta -transus for 30 minutes, quenching and then tempering at a temperature of 5000[deg] C+- 5[deg] C for a period of 8 hours so to obtain a hardness of greater than 490 HV.