Composite tooth for working the ground or rock

1. A composite tooth for working the ground or rocks, said tooth comprising a ferrous alloy at least partially reinforced ( 5 ) with titanium carbide according to a defined geometry, wherein said reinforced portion ( 5 ) comprises an alternating macro-microstructure of millimetric areas ( 1 ) concentrated with micrometric globular particles of titanium carbide ( 4 ) separated by millimetric areas ( 2 ) essentially free of micrometric globular particles of titanium carbide ( 4 ), said areas concentrated with micrometric globular particles of titanium carbide ( 4 ) forming a microstructure in which the micrometric interstices ( 3 ) between said globular particles ( 4 ) are also filled by said ferrous alloy.

2. The tooth according to claim 1 , wherein said millimetric concentrated areas have a concentration of micrometric globular particles of titanium carbide ( 4 ) greater than 36.9% by volume.

3. The tooth according to claim 1 , wherein said reinforced portion has a global titanium carbide content between 16.6 and 50.5% by volume.

4. The tooth according to claim 1 , wherein the micrometric globular particles of titanium carbide ( 4 ) have a size of less than 50 μm.

5. The tooth according to claim 1 , wherein the major portion of the micrometric globular particles of titanium carbide ( 4 ) has a size of less than 20 μm.

6. The tooth according to claim 1 , wherein said areas concentrated with globular particles of titanium carbide ( 1 ) comprise 36.9 to 72.2% by volume of titanium carbide.

7. The tooth according to claim 1 , wherein said areas concentrated with titanium carbide ( 1 ) have a dimension varying from 1 to 12 mm.

8. The tooth according to claim 1 , wherein said areas concentrated in titanium carbide ( 1 ) have a dimension varying from 1 to 6 mm.

9. The tooth according to claim 1 , wherein said areas concentrated in titanium carbide ( 1 ) have a dimension varying from 1.4 to 4 mm.

10. A method for manufacturing by casting a composite tooth according to claim 1 , comprising the following steps:

providing a mold comprising the imprint of the tooth with a predefined reinforcement geometry;

introducing, into the portion of the imprint of the tooth intended to form the reinforced portion ( 5 ), a mixture of compacted powders comprising carbon and titanium in the form of millimetric granules precursor of titanium carbide;

casting a ferrous alloy into the mold, the heat of said casting triggering an exothermic self-propagating high temperature synthesis (SHS) of titanium carbide within said precursor granules;

forming, within the reinforced portion ( 5 ) of the tooth, an alternating macro-microstructure of millimetric areas concentrated ( 1 ) with micrometric globular particles of titanium carbide ( 4 ) at the location of said precursor granules, said areas being separated from each other by millimetric areas ( 2 ) essentially free of micrometric globular particles of titanium carbide ( 4 ), said globular particles ( 4 ) being also separated within said millimetric areas concentrated ( 1 ) with titanium carbide by micrometric interstices ( 3 );

infiltration of the millimetric ( 2 ) and micrometric ( 3 ) interstices by said high temperature cast ferrous alloy, following the formation of microscopic globular particles of titanium carbide ( 4 ).

11. The manufacturing method according to claim 10 , wherein the mixture of compacted powders of titanium and carbon comprises a powder of a ferrous alloy.

12. The manufacturing method according to claim 10 , wherein said carbon is graphite.

13. The tooth obtained according to claim 10 .