METHOD FOR MAKING A SEALED PASSAGE IN A REFRACTORY COMPOSITE PART, AND APPLICATION TO THE PRODUCTION OF A REFRACTORY COMPOSITE STRUCTURE COOLED BY FLUID CIRCULATION

A sealed passage is formed in a part of refractory composite material by inserting a tubular metal lining in a hole in the part, brazing material being interpose between the lining and the hole, and by heating to braze the metal lining to the wall of the hole, so that the metal lining defines a sealed passage (38). The metal liming (39) is plastically deformable under the conditions of use of the part such that differential expansion of thermal origin between the refractory composite material and the metal lining can be compensated by plastic deformation of the lining. The method is particularly applicable to providing thermal protection that is cooled by the flow of a cooling fluid, and that is suitable for a deflector in an electromagnetic confinement chamber for a plasma in an installation for controlled thermonuclear fusion, said protection being constituted by a plurality of elements (30) made of refractory composite material and having sealed internal passages (38) connected to pipework (40, 42) for feeding and removing a cooling fluid.