METHOD OF DEPOSITING A THERMAL BARRIER BY PLASMA TORCH

Abstract

The invention relates to the field of methods of depositing a material on a substrate. It relates to a method of depositing, onto a substrate, a material that acts as a thermal barrier and that prior to deposition is in powder form. The powder is introduced into the plasma jet of a first plasma torch and into the plasma jet of at least one second plasma torch, the first plasma torch and at least the second plasma torch being disposed in an enclosure and oriented in such a manner that their plasma jets cross, so as to create a resultant plasma jet in which the powder is vaporized, the substrate being placed on the axis of the resultant plasma jet.

Description

BRIEF DESCRIPTION OF THE DRAWING

The invention can be better understood and its advantages appear better on reading the following detailed description of an embodiment by way of non-limiting example. The description refers to the accompanying drawing, in which:

FIG. 1 is an overall view of an installation enabling the method of the invention to be implemented; and

FIG. 2 is a view showing plasma jets crossing, together with the resulting plasma.

Claims

1. A method of depositing, onto a substrate, a material acting as a thermal barrier, said material being in powder form prior to deposition, wherein said powder is introduced into the plasma jet of a first plasma torch and into the plasma jet of at least one second plasma torch, the first plasma torch and at least the second plasma torch being disposed in an enclosure and oriented in such a manner that their plasma jets cross, so as to create a resultant plasma jet in which said powder is vaporized, said substrate being placed on the axis of said resultant plasma jet.

2. A method according to claim 1, wherein only two of said plasma torches are used.

3. A method according to claim 1, wherein pressure in said enclosure is reduced.

4. A method according to claim 1, wherein the axes of said torches constitute generator lines of a cone of central axis, the axis of each of said torches forming, relative to the central axis of the cone, an angle lying in the range 20° to 60°, the central axis of the cone being directed towards the surface of the substrate that is to receive the material to be deposited.

5. A method according to claim 1, wherein the distance D between each of said torches and said substrate lies in the range 50 mm to 500 mm.

6. A method according to claim 1, wherein said material is a ceramic.

7. A method according to claim 6, wherein ceramic is selected from a group comprising yttrium zirconia, and zirconia optionally stabilized with at least one of the oxides selected from the following list: CaO, MgO, CeO2, and rare earth oxides.

8. A method according to claim 1, wherein said substrate may include a bonding underlayer at its surface onto which said material acting as a thermal barrier is deposited.

9. A method according to claim 1, wherein said material introduced in powder form into each of said torches is different from one torch to the other.

10. An installation for depositing, onto a substrate, a material acting as a thermal barrier, said material being in powder form prior to deposition, the installation comprising an enclosure having said substrate disposed therein, a first plasma torch, and at least one second plasma torch disposed in said enclosure in such a manner that when said powder is introduced into the plasma jet of said first plasma torch and into the plasma jet of at least said second plasma torch, the plasma jet of said first plasma torch and the plasma jet of said second plasma torch cross, thereby creating a resultant plasma jet in which said powder is vaporized, said substrate being placed on the axis of said resultant plasma jet.

11. An installation according to claim 10, wherein the inside diameter of each of said torches is greater than 6 mm.

12. A thermomechanical part obtained by a method according to claim 1.