A sintered material based on silicon carbide (SiC) reactively sintered between 1,100.degree. C. and 1,700.degree. C. to form a silicon nitride binder (Si.sub.3N.sub.4), intended in particular for fabricating an aluminum electrolysis cell, including 0.05% to 1.5% of boron, the Si.sub.3N.sub.4/SiC weight ratio being in the range 0.05 to 0.45. Application, in particular, to an electrolysis cell.