A method of fabricating three-dimensional parts out of an alloy of aluminum and titanium

A method of fabricating a sintered three-dimensional part comprising a titanium-based alloy, the method comprising:

• preparing an injection composition comprising a binder and a powder of a titanium-based alloy including aluminum and/or chromium as alloying addition element(s);
• injecting the injection composition into a cavity of a mold so as to obtain a blank for the part to be made;
• selectively eliminating the binder present in the blank;
• a first step of sintering the powder of titanium-based alloy, the powder being subjected during the first sintering step to a first pressure that is higher than or equal to 1 mbar in order to obtain a preform of the part made of sintered alloy powder;
• and
• a second sintering step, performed after the first sintering step, during which a second pressure is imposed, the second pressure being lower than the first pressure, the duration for which the second pressure is applied being selected so that the content by weight of aluminum and/or chromium in a layer having a thickness of 200 μm situated at the surface of the preform does not vary by more than 5% in relative value as a result of the second sintering step.