Process for manufacturing a tubular component with an insert made of a metal matrix composite

1. A process for manufacturing a tubular component comprising an insert made of a metal matrix composite, within which ceramic fibers extend, said process comprising:

placing filaments next to each other, wherein each filament comprises a ceramic fiber coated with a metal sheath, such that the metal sheath of each filament contacts the metal sheath of an adjacent filament;

welding said filaments together by laser spot welding by directing a laser beam toward contact points between two adjacent filaments so that said laser beam is perpendicular to said adjacent filaments at said contact points, wherein said laser spot welding is performed by sequentially exposing contact points of different pairs of adjacent filaments to said laser beam thereby forming an interrupted weld across a transverse direction of a bonded sheet; and

draping said bonded sheet of coated filaments around a metal mandrel.

2. A process for manufacturing a tubular component according to claim 1 , wherein said draping of said bonded sheet is performed by wounding a beveled end of the bonded sheet around one end of the mandrel and then draping the bonded sheet in a helical manner around the circumference of the mandrel.

3. A process for manufacturing a tubular component according to claim 1 , further comprising at least one additional step of laying up another bonded sheet of coated filaments around an already draped bonded sheet.

4. A process for manufacturing a tubular component according to claim 1 , further comprising;

inserting the mandrel and the bonded sheet into a metal sheath; and

compacting said metal sheath with said mandrel and bonded sheet inserted therein by hot isostatic pressing.

5. A process for manufacturing a tubular component according to claim 4 , further comprising, before the hot isostatic pressing, a step of welding each end of the mandrel to a circular metal plate.

6. A process for manufacturing a tubular component according to claim 1 , wherein said placing of the filaments includes warping and driving the filaments side by side, by a drive module, past a laser welding device, which forms spot welds between the adjacent filaments.

7. A process for manufacturing a tubular component according to claim 1 , further comprising fastening the bonded sheet to the mandrel with a contact welding process between two electrodes and passage of a medium-frequency current, wherein an electrode is applied to the bonded sheet and an electrode is applied to its support, and current passes in order to induce welding by solid-state diffusion.

8. A process for manufacturing a tubular component according to claim 7 , further comprising fastening the bonded sheet at its ends both at the start and at the finish of the draping step.

9. A process for manufacturing a tubular component according to claim 7 , wherein the bonded sheet is fastened along a longitudinal band.

10. A process for manufacturing a tubular component according to claim 1 , wherein said placing of said filaments next to each other is performed such that the filaments are placed in one and a same plane.

11. A process for manufacturing a tubular component according to claim 10 , wherein said welding of said filaments is performed by directing said laser beam perpendicularly to said plane in which said filaments are placed.

12. A process according to claim 11 , further comprising adjusting the rigidity of said bonded sheet by adjusting a distance between successive weld spots.

13. A process according to claim 11 , wherein said process is free of any step of adding a binder throughout said manufacturing of said tubular component.

14. A process according to claim 11 , wherein said process is free of any step of removing a binder throughout said manufacturing of said tubular component.

15. A process for manufacturing a tubular component according to claim 1 , further comprising a step of adjusting welding parameters of said laser spot welding such that weld pools at said contacts point do not flow out.

16. A process for manufacturing a tubular component according to claim 1 , wherein said laser spot welding is performed in an inert atmosphere.

17. A process for manufacturing a tubular component according to claim 16 , wherein said laser spot welding is performed in an argon atmosphere.

18. A process according to claim 1 , further comprising a step of winding the welded filaments before said step of draping, and wherein said process is free of a step of pressing said filaments with rollers between said welding step and said winding step.

19. A process according to claim 1 , wherein said laser spot welding is concentrated at said contact points such that said laser beam is not directed toward said ceramic fibers and such that said ceramic fibers are not affected by a local melting of the metal sheath caused by said laser beam at said contact points.