The invention relates to a preparation method of a
composite material box body with an inner boss, in particular to a preparation method of a SiC / SiBCN
ceramic matrix
composite material box body with an inner boss. In order to overcome the defects that in the prior art, the preparation process of a composite box body with an inner boss is complex, holes are formed in areas with different thicknesses, and hole filling
fiber bundles are prone to deformation and
dislocation after being pressed, so that the structure is unstable. The preparation method of the SiC / SiBCN
ceramic matrix composite box with the inner boss sequentially comprises the steps of
SiC fiber prefabricated body preparation, high-
temperature treatment,
boron nitride interface layer preparation, Si3N4 matrix deposition, SiBCN matrix preparation, Si3N4 matrix deposition and the like, the
SiC fiber prefabricated body is prepared from a U-shaped prefabricated body, a concentric-square-shaped prefabricated body and an exterior prefabricated body, and the stability of the mounting boss is improved.