Materials and parts that can withstand high temperatures in an oxidizing medium, and method for manufacturing same

A method of making a part out of refractory material that can withstand high temperatures in an oxidizing medium, the method comprising the steps of:

• making a composition comprising at least:
• hafnium, or a non-oxide compound of hafnium, or a mixture of hafnium and a non-oxide compound of hafnium;
• boron or a non-oxide compound of boron, or a mixture of boron and a nonoxide compound of boron;
• and
• a constituent corresponding to a rare earth element RE or to a non-oxide compound of the rare earth element RE, or corresponding to a mixture of rare earth element RE and a non-oxide compound of rare earth element RE, where RE is selected from scandium, yttrium, and the lanthanides;
• wherein the composition contains (i) a nitride of said rare earth element RE and at least one boride of hafnium and at least one non-oxide compound of hafnium, or (ii) hafnium and a boride of rare earth element RE, or (iii) a hafnium carbide and a boride of rare earth element RE;
• said composition containing no silicon or compound silicon;
• and
• shaping the composition and densifying said composition.

A method of making a protective layer that can withstand high temperatures in an oxidizing medium, the layer being made on a composite material part constituted at least in part by carbon, said method comprising the steps of:

• applying on the part a composition comprising at least:
• hafnium, or a non-oxide compound of hafnium, or a mixture of hafnium and a non-oxide compound of hafnium;
• boron or a non-oxide compound of boron, or a mixture of boron and a non-oxide compound of boron;
• and
• a constituent corresponding to a rare earth element RE or to a non-oxide compound of a rare earth element RE, or corresponding to a mixture of rare earth element RE and a non-oxide compound of the rare earth element RE, where RE is selected from scandium, yttrium, and the lanthanides;
• said composition containing no silicon or silicon compound;
• and
• shaping the composition and densifying said composition.

A method of using a part at a temperature higher than 2000° C. in an oxidizing medium, the method comprising:

• providing the part, the part being a refractory part or a composite material part;
• and
• using said refractory part or said composite material part under a temperature higher than 2000° C. in an oxidizing medium, wherein
• said refractory part is constituted by a refractory material that can withstand high temperatures in the oxidizing medium, and
• said composite material part constituted at least in part by carbon and having a protective coating providing protection at said high temperatures in the oxidizing medium, wherein said protective coating is constituted by at least the refractory material,
• the refractory material comprising:
• hafnium, or a non-oxide compound of hafnium, or a mixture of hafnium and a non-oxide compound of hafnium;
• boron or a non-oxide compound of boron, or a mixture of boron and a nonoxide compound of boron;
• and
• a constituent corresponding to a rare earth element RE or a to non-oxide compound of the rare earth element RE, or corresponding to a mixture of rare earth element RE and a non-oxide compound of the rare earth element RE, where RE is selected from scandium, yttrium, and the lanthanides;
• and
• said material containing neither silicon nor a compound of silicon.