Abstract: A substrate characterised in that it is at least partially surface-coated with a coating containing at least one so-called “barrier” layer having silica and one or more material(s) X selected from among SiC, Si, Si3N4, in which layer the amount of X varies between 25-wt. % and 50.-wt. % in relation to the total weight of the barrier layer, the barrier layer being formed by grains of one or more materials X covered at least partially in a silica shell, and the barrier layer being in direct contact with the substrate.

Abstract: A substrate, in particular intended for contact with liquid silicon, wherein it is at least partially surface-coated with a multilayer coating formed by: at least one layer, known as the adhesion layer, contiguous with the substrate, having an open porosity of at least 30%, and formed of a material comprising silica and silicon nitride, said material having a silica content of between 10 wt.-% and 55 wt.-% in relation to the total weight thereof; and a layer different from the adhesion layer, known as the release layer, located on the surface of the adhesion layer and formed of a material including silica and silicon nitride, said material having a silica content of between 2 wt.-% and 10 wt.-% in relation to the total weight thereof.

Abstract: A substrate, in particular intended for contact with liquid silicon, wherein it is at least partially surface-coated with a multilayer coating formed by: at least one layer, known as the adhesion layer, contiguous with the substrate, having an open porosity of at least 30%, and formed of a material comprising silica and silicon nitride, said material having a silica content of between 10 wt.-% and 55 wt.-% in relation to the total weight thereof; and a layer different from the adhesion layer, known as the release layer, located on the surface of the adhesion layer and formed of a material including silica and silicon nitride, said material having a silica content of between 2 wt.-% and 10 wt.-% in relation to the total weight thereof.

Abstract: A substrate characterised in that it is at least partially surface-coated with a coating containing at least one so-called “barrier” layer having silica and one or more material(s) X selected from among SiC, Si, Si3N4, in which layer the amount of X varies between 25-wt. % and 50.-wt. % in relation to the total weight of the barrier layer, the barrier layer being formed by grains of one or more materials X covered at least partially in a silica shell, and the barrier layer being in direct contact with the substrate.

Abstract: The invention relates to a process for producing a thermogenerator (10) comprising a plurality of thermocouples formed of p-type thermoelements (12) and n-type thermoelements (14). A wafer (18), provided with a plurality of holes (20a, 20b) is covered in thermoelectric material powder (22, 24). Pressure (P) is applied to the powder (22, 24) so that it penetrates into the holes (20a, 20b) while heating so as to form a plurality of p-type and n-type thermoelements (12, 14) contained in the wafer (18). The wafer (18) is thinned, the thinned wafer thus forming a matrix (16) in which the thermoelements (12, 14) are contained. While preserving the matrix (16) the p-type thermoelements are connected so as to form thermocouples and the n-type thermoelements are connected so as to form thermocouples, thereby obtaining a thermogenerator (10).