Abstract: A method for producing a hollow part (17; 21; 46) made of a metal material, includes preparing a blank (1; 18; 33) of the metal material of the hollow part (17; 21; 46), and at least one sacrificial mandrel (2; 19; 34, 35) made of a material which has a yield stress in the range from ?30% to +20% of the yield stress of the material of the blank (1; 18; 33), preferably in the range from ?15% to +10%, ideally in the range from ?5% to +3%; applying a punch (10) on at least one of the ends of the blank (1; 18; 33) in order to produce the expansion of at least a portion of said blank (1; 18; 33) and to create at least one internal space (12; 20; 36, 37) inside said blank (1; 18; 33); inserting a sacrificial mandrel (2; 19; 34; 35) in said an internal space (12; 20; 37) of the blank (1; 18; 33);crimping the sacrificial mandrel (2; 19; 34, 35) in said blank (1; 18; 33);producing, by co-forging, a simultaneous deformation of said blank (1; 18; 33) and of said sacrificial mandrel (2; 19; 34, 35), with a homothetic rat

Abstract: The invention relates to a process for the preparation of a part made of titanium alloy, comprising a thermal treatment for relaxing the internal stresses of the part, the thermal treatment comprising maintaining at a temperature “T1” greater than the beta transus (beta transition) temperature, referred to as “Tbt”, and the part being free to deform by creeping. The invention also relates to a tool for carrying out this process.