A process for manufacturing a composite material comprising a substrate and a coating based on powder, comprising a) functionalizing the substrate by OH groups, said functionalizing comprising treating a surface of said substrate with a first solution containing at least one first solvent, chosen from the group consisting of water and organic alcohols, with a linear chain, saturated or unsaturated, comprising at least one alcohol function, and preferably chosen from the group of methoxyethanol, ethanol, ethylene glycol, 1-propanol, methanol, n-butanol, 2-phenylethanol and 2-propanol and mixtures thereof, b) functionalizing in a second solvent of a first powder comprising an alkali oxide, an alkaline earth oxide, a transition metal oxide, a poor metal oxide, a metalloid oxide, a lanthanide oxide or an actinide oxide, preferably a metal oxide and/or a silicon oxide, more preferably comprising one or more oxides chosen from the group of oxides of lithium, of sodium, of cerium, of titanium, of vanadium, of chromium, of molybdenum, of manganese, of iron, of cobalt, of palladium, of copper, of zinc, of cadmium, of aluminium, of silicon, of tin and lead and combinations thereof, such as mixed oxides of cobalt and lithium, iron and manganese, lithium and titanium, with an agent bearing a carboxyl or carboxylate function and formation of a first stable colloidal sol based on said first powder, functionalized by said agent bearing a carboxyl or carboxylate function, c) at least one application of at least one layer of said first colloidal sol on the functionalized substrate, d) drying said at least one layer of said first colloidal sol and e) forming a first coating layer formed by said first colloidal sol, adhering to said substrate, by heating at a temperature above 50°C and below 500°C, said coating being formed from said first powder uniformly distributed. a) functionalizing the substrate by OH groups, said functionalizing comprising treating a surface of said substrate with a first solution containing at least one first solvent, chosen from the group consisting of water and organic alcohols, with a linear chain, saturated or unsaturated, comprising at least one alcohol function, and preferably chosen from the group of methoxyethanol, ethanol, ethylene glycol, 1-propanol, methanol, n-butanol, 2-phenylethanol and 2-propanol and mixtures thereof, b) functionalizing in a second solvent of a first powder comprising an alkali oxide, an alkaline earth oxide, a transition metal oxide, a poor metal oxide, a metalloid oxide, a lanthanide oxide or an actinide oxide, preferably a metal oxide and/or a silicon oxide, more preferably comprising one or more oxides chosen from the group of oxides of lithium, of sodium, of cerium, of titanium, of vanadium, of chromium, of molybdenum, of manganese, of iron, of cobalt, of palladium, of copper, of zinc, of cadmium, of aluminium, of silicon, of tin and lead and combinations thereof, such as mixed oxides of cobalt and lithium, iron and manganese, lithium and titanium, with an agent bearing a carboxyl or carboxylate function and formation of a first stable colloidal sol based on said first powder, functionalized by said agent bearing a carboxyl or carboxylate function, c) at least one application of at least one layer of said first colloidal sol on the functionalized substrate, d) drying said at least one layer of said first colloidal sol and e) forming a first coating layer formed by said first colloidal sol, adhering to