PROCEDE DE FABRICATION D'UN MATERIAU COMPOSITE CERAMIQUE A BASE DE NITRURE DE SILICIUM ET DE BETA-EUCRYPTITE

Procédé de fabrication d'un composite céramique fritté à base de nitrure de silicium et de p-eucryptite comprenant une étape de réalisation d'un premier mélange (101) d'une poudre de nitrure de silicium sous forme cristalline et d'une poudre d'un premier aluminosilicate de lithium sous forme cristalline dont la composition est la suivante (Li2O)x (Al2O3)y (SiO2)z, la composition d'aluminosilicate de lithium étant telle que l'ensemble des fractions molaires (x, y, z) est différent de l'ensemble (1, 1, 2). The process of fabricating a sintered ceramic composite material made of silicon nitride and beta -eucryptite materials, comprises creating (101) a first mixture of silicon nitride powder in crystalline form and a powder of a first lithium aluminosilicate in crystalline form, performing (105) a first heat treatment on silicon nitride composite and the first lithium aluminosilicate obtained from the first mixture to sinter silicon nitride and to obtain a ceramic composite made of silicon nitride and beta -eucryptites, and performing a second heat treatment to crystallize the beta -eucryptites. The process of fabricating a sintered ceramic composite material made of silicon nitride and beta -eucryptite materials, comprises creating (101) a first mixture of silicon nitride powder in crystalline form and a powder of a first lithium aluminosilicate in crystalline form, performing (105) a first heat treatment on silicon nitride composite and the first lithium aluminosilicate obtained from the first mixture to sinter silicon nitride and to obtain a ceramic composite made of silicon nitride and beta -eucryptites, and performing a second heat treatment to crystallize the beta -eucryptites. The lithium aluminosilicate composition is represented as (Li 2O) x(Al 2O 3) y(SiO 2) z, where entire molar fractions (x, y, z) is different from (1, 1, 2). The first heat treatment is carried out at a first temperature greater than melting temperature of beta -eucryptite under the operating conditions. The second heat treatment is carried out by maintaining the ceramic composite and beta -eucryptite at a temperature of 500-800[deg] C, and comprises performing nucleation at a specified temperature and growth at a temperature greater than the nucleation temperature. The silicon nitride powder is washed to remove the silica polluting the powder before mixing it with the lithium aluminosilicate. The first lithium aluminosilicate powder is fabricated by producing a mixture of lithium