Abstract: A method of coating the surface of a metal substrate includes a) applying a first composition on the surface of a metal substrate, the first composition being a solution comprising a liquid medium including sol-gel precursors of alcoxysilane type or of metallo-organic type; b) subjecting the first composition to first heat treatment to form an anchor layer on the metal substrate in which the sol-gel precursors are bonded to the metal substrate, a first temperature being imposed during the first heat treatment that is sufficient to eliminate all or part of the liquid medium and to encourage the bonding of the sol-gel precursors to the metal substrate; and c) applying a second composition on the anchor layer. The second composition includes coating compounds to obtain a coating on the anchor layer by forming bonds between the sol-gel precursors and the coating compounds.

Abstract: A method of coating the surface of a metal substrate includes a) applying a first composition on the surface of a metal substrate, the first composition being a solution comprising a liquid medium including sol-gel precursors of alcoxysilane type or of metallo-organic type; b) subjecting the first composition to first heat treatment to form an anchor layer on the metal substrate in which the sol-gel precursors are bonded to the metal substrate, a first temperature being imposed during the first heat treatment that is sufficient to eliminate all or part of the liquid medium and to encourage the bonding of the sol-gel precursors to the metal substrate; and c) applying a second composition on the anchor layer. The second composition includes coating compounds to obtain a coating on the anchor layer by forming bonds between the sol-gel precursors and the coating compounds.

Abstract: A lithographic method, products obtained thereby and use of the method, in particular, in the production of micro- or nano-metric products or objects. The method includes the steps of deposition of a film of an organometallic solution of a substrate, containing at least one metal ion as precursor(s) for marking the substrate, local exposure, according to the required pattern, of the obtained film, via at least one focussed energetic beam, with an energy density sufficient to at least locally dry the film, dissolution of the non-exposed zone, the at least dried zones remaining on the substrate, optionally subjecting the obtained product to a thermal treatment and, where necessary, repetition of certain steps, with optional change to the organometallic solution, until the required final product is obtained.

Abstract: The present invention relates to a cordierite (2MgO.2Al.sub.2 O.sub.3.5SiO.sub.2) type ceramic powder sintering at low-temperature defined in that its composition is: 60 to 50% SiO.sub.2, 5 to 20% MgO and 20 to 40% Al.sub.2 O.sub.3, and in that its specific surface area is not less than 50 m.sup.2 /g, this powder having a fritting temperature of less than 1,100.degree. C.The invention also relates to a process for the preparation of this powder, which consists in preparing a mixed alcoholic solution of an aluminum and silicon salt, in preparing a solution of an alcohol-soluble magnesium salt, in mixing the two solutions, in padding a hydrolyzing agent in the form of a totally volatile weak base to the solution, which leads to the formation of a gel, in subjecting the said gel to a first thermal treatment at a temperature not exceeding 450.degree. C., and in subjecting the said powder to a second thermal treatment at a temperature of between 450.degree. C. and 900.degree. C.