Method for preparing a carbide ceramics multilayer coating on, and optionally in, a part made of a carbon-containing material using a reactive melt infiltration RMI technique

A method for preparing a metals carbides multilayer coating on at least one surface of a first carbon layer of a substrate, or on the surface and under the surface inside the first carbon layer, by a reactive melt infiltration technique, the method comprising:

• the following successive a) to d) being carried out:
• a) putting the at least one surface into contact with a solid metal disilicide MSi2, wherein M is selected from hafnium, titanium, and tantalum;
• b) heating the substrate and the metal disilicide up to a temperature TP above the melting temperature of the metal disilicide;
• c) observing a plateau at the temperature TP for a sufficient duration so that the metal disilicide reacts with carbon of the first carbon layer and forms a first multilayer coating comprising a dense and continuous layer of SiC, fully covered by a dense and continuous layer of MC;
• d) cooling the part provided with the first multilayer coating;
• and then, at the end of d), the following e) is further carried out, and then the following successive f) to i) are carried out, or the following successive f) to i) are carried out without e);
• e) depositing a second carbon layer at the surface of the first multilayer coating;
• f) putting the surface of the first multilayer coating still containing the carbon of the first carbon layer or the surface of the second carbon layer into contact with a solid metal disilicide MSi2, wherein M is selected among hafnium, titanium, and tantalum;
• g) heating the surface of the first multilayer coating still containing said carbon of the first carbon layer and the metal disilicide, or the second carbon layer and the metal disilicide, to a temperature TP above the melting temperature of the metal disilicide;
• h) observing a plateau at a temperature TP for a sufficient duration so that the metal disilicide reacts with the carbon of the first carbon layer or with carbon of the second carbon layer and forms a second multilayer coating comprising a dense and continuous layer of SiC, fully covered by a dense and continuous layer of MC;
• i) cooling the part provided with the second multilayer coating;
• and then at the end of i), optionally the following j) is further carried out;
• j) depositing a third carbon layer at the surface of the second multilayer coating;
• and at the end of i) or of j), the following k) is further carried out;
• k) carrying out silicidation of the surface of the second multilayer coating still containing carbon or of the third carbon layer with liquid Si, whereby a SiC layer is obtained on the second multilayer coating.