Reagent composition and method of brazing of ceramic materials containing alumina

The invention relates to a composition and a reactive brazing process of ceramic materials containing alumina. This composition comprises at least one precious metal selected from Pd, Pt and Au, and magnesium, preferably at most 5 % by weight of magnesium. Brazing is performed at a temperature of 1300 to 1600 deg.C in the absence of hydrogen.