Method and machine for additive manufacturing reducing risks of powder dissemination during manipulations

1. An additive manufacturing method for an object using at least one powder contained in a solid block along with a sublimatable material, the method comprising the following steps in succession:

(1) loading the solid block in a loading space of an additive manufacturing machine;

(2) sublimating a portion of said sublimatable material present in the solid block and recovering a portion said at least one powder released by the sublimating; and

(3) additive manufacturing the object by stacking successive layers made using the at least one powder recovered in step (2).

2. The additive manufacturing method according to claim 1 , further comprising, after said step (3), recovering a portion of the sublimated material sublimated in step (2) using a cold trap.

3. The additive manufacturing method according to claim 1 , wherein said sublimatable material is cyclododecane.

4. The additive manufacturing method according to claim 1 , further comprising manufacturing the solid block by:

mixing said at least one powder and a portion of said sublimatable material so as to obtain a non-powdery material;

compacting the non-powdery material at ambient temperature;

melting a portion of said sublimatable material on an external surface of the compacted non-powdery material, so as to obtain a solid external wall of the solid block with a given thickness after cooling.

5. The additive manufacturing method according to claim 1 , further comprising manufacturing the solid block by:

making a container using said sublimatable material, said container comprising a body defining an internal cavity and an element to close said internal cavity;

introducing the at least one powder into the internal cavity;

closing the internal cavity using said closing element.

6. The additive manufacturing method according to claim 1 , further comprising manufacturing the solid block by:

bringing said sublimatable material in liquid form into a mould and then pouring the at least one powder into the mould containing said sublimatable material in liquid form, or vice versa;

cooling said sublimatable material so as to obtain the solid block of material containing the at least one powder.

7. The additive manufacturing method according to claim 1 , further comprising manufacturing the solid block by:

placing the at least one powder in a mould;

impregnating the at least one powder around a periphery of the mould, using a material in liquid form to a given thickness, so as to obtain a solid external wall of the solid block after cooling over said given thickness.

8. The additive manufacturing method according to claim 1 , wherein said additive manufacturing step of the object is done using one of the following techniques:

selective laser melting or electron beam melting;

selective laser sintering or electron beam sintering; and

projecting a binder on successive layers of the portion of the at least one powder released by the step (2).

9. The additive manufacturing method according to claim 1 , wherein said powder is chosen from among:

metallic powders;

organic powders; and

inorganic powders.

10. The additive manufacturing method according to claim 1 , wherein the at least one powder comprises at least one of a titanium alloy, an aluminium alloy, a nickel alloy, a superalloy, steel, stainless steel, a refractory metal, a precious metal, a pure metal or an alloyed metal.

11. The additive manufacturing method according to claim 1 , wherein the at least one powder comprises at least one of polyether block amide, polystyrene, polyetheretherketone (PEEK), polyaryletherketone (PAEK), and a polyamide containing aluminum.

12. The additive manufacturing method according to claim 1 , wherein the at least one powder comprises at least one of quartz, ceramic, and calcium sulphate.

13. The additive manufacturing method according to claim 1 , further comprising a step (4), after the additive manufacturing step, of at least partially coating an assembly composed of unbonded powder and the object surrounded by the unbonded powder, the coating being made by a sublimatable material.

14. The additive manufacturing method according to claim 13 , further comprising, after the coating step (4):

extracting and transferring the coated assembly from the additive manufacturing machine to another work station for extraction of said object.

15. The additive manufacturing method according to claim 13 , wherein the coating is made using at least some of said material recovered during step (2).

16. The additive manufacturing method according to claim 13 , wherein the coating is made using all of said material recovered during step (2).

17. The additive manufacturing method according to claim 13 , wherein a sub-portion of said sublimated material sublimated in step (2) is applied around said assembly in a liquid state so as to impregnate by capillarity a portion of the at least one powder recovered in step (2).

18. The additive manufacturing method according to claim 17 , wherein the application comprises direct application of the sub-portion of said sublimated material.

19. The additive manufacturing method according to claim 17 , wherein the application comprises sprinkling the sub-portion of said sublimated material.

20. The additive manufacturing method according to claim 17 , wherein the application comprises spraying the sub-portion of said sublimated material around said assembly.