Casting method for obtaining a part including a tapering portion

1. A casting method for obtaining a blade for a turbine engine that includes a tapering trailing edge, the method comprising:

providing an insert element having a tapering section;

making a shell around the insert element; and

casting a molten material into said shell including the insert element,

wherein said tapering trailing edge of the blade is constituted by said tapering section of said insert element wherein the molten material is a material from the family of metals.

2. A method according to claim 1 , wherein the making the shell comprises, in order:

providing a mold reproducing a shape of the blade that is to be obtained;

inserting the insert element in said mold in a location corresponding to the trailing edge of the blade that is to be obtained;

injecting wax into said mold and obtaining a wax model including the insert element;

molding the shell around the wax model including the insert element; and

firing the shell and removing the wax.

3. A method according to claim 2 , wherein the mold is a reusable metal mold.

4. A method according to claim 1 , wherein the insert element includes recesses into which the molten material can penetrate during casting.

5. A method according to claim 1 , wherein the insert element is heated to a temperature close to that of the molten material during casting.

6. A method according to claim 1 , wherein a thickness of the tapering section of the insert element is less than 1 mm.

7. A method according to claim 1 , wherein the insert element includes a composite material.

8. A method according to claim 7 , wherein the shell includes a cavity presenting a shape of a main portion of the obtained blade, and the obtained blade presents a transition zone between the main portion and the insert element, in which transition zone the molten material and material of the insert element are in solid solution.

9. A method according to claim 1 , wherein the molten material is a titanium-aluminum alloy.