Method for manufacturing pieces made of ceramic material by the technique of additive manufacturing

A method for manufacturing a piece made of ceramic material by the technique of additive manufacturing or stereolithography, said piece being formed in the green state from a photocurable ceramic composition comprising a ceramic powder and an organic portion able to be destroyed by heating during the debinding and including at least one photocurable monomer and/or oligomer and at least one photoinitiator, and then being subjected to debinding and sintering operations,

• wherein:
• on a working platform (1) of a stereolithography machine, is manufactured, by the technique of additive manufacturing, simultaneously but separately, from a same pasty photocurable ceramic composition:
• a green assembly made up of a support (2) of the green piece and of said green piece on said support (2), the free surface of the latter bearing the imprint (2a) of a first face of said green piece, said imprint (2a) made in said support having a surface shifted in XYZ but equivalent to said first face of said green piece so as to allow it to be received in said support (2) and the spacing between both being filled with pasty material able to be removed once said green assembly is formed;
• and
• a green shaper (4) made up of a piece made of ceramic material the free surface of which bears the imprint (4a) of a second face of said green piece opposed to said first face, said imprint (4a) made in said shaper (4) having a surface shifted in XYZ but equivalent to said second face of said green piece so as to allow it to be received in said shaper (4);
• in an oven, is placed, on said green shaper (4) thus obtained with its imprint (4a) turned upwards, said green assembly thus obtained with its green piece turned downwards in order for it to be received in the imprint (4a) of said shaper (4), and the green piece thus held between the shaper (4) and the support (2) is subjected to debinding and to sintering, the imprints (2a;
• 4a) of the support and of the shaper being such that the piece is completely enclosed between them during the debinding and sintering operations.