Process and apparatus for making ceramic articles
AssigneeGlaverbel
InventorsJean-Pierre Meynckens, Jean-Pierre Robert
Life of this patent
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Abstract
A process and apparatus for making a ceramic article, especially pipes and tubes of ceramic material such as silicon carbide, in which the article is formed by projecting a ceramic powder mixture comprising refractory particles and combustible particles against a smooth-surface metal former which is heated to a temperature of at least 850.degree. C. where in the presence of an oxygen-rich gas the combustible particles react exothermically to produce from the refractory particles and the reaction product of the combustible particles a coherent refractory article in the shape of the former.
Claims19
A process for making a ceramic article, comprising:
- a. providing a powder mixture comprised of refractory particles and combustible particles which react exothermically;
- b. heating a metal former to a temperature of at least 850.degree. C.;
- c. projecting the powder mixture against the metal former, either before or after heating the metal former to a temperature of at least 850.degree. C., in the presence of an oxygen-rich gas so that the combustible particles react exothermically and produce a ceramic article on the metal former from the refractory particles and the reaction product of the combustible particles, which ceramic article is comprised of a coherent refractory material and has a shape which conforms to that of the metal former;
- and
- d. separating the metal former from the ceramic article.
A process for making a ceramic article, comprising:
- a. providing a metal former and pre-coating the metal former with a refractory cement;
- b. heating the metal former to a temperature of at least 850.degree. C.;
- c. providing a powder mixture comprised of refractory particles and combustible particles which react exothermically;
- d. projecting the powder mixture against the metal former, either before or after heating the metal former to a temperature of at least 850.degree. C., in the presence of an oxygen-rich gas so that the combustible particles react exothermically and produce a ceramic article on the metal former from the refractory particles and the reaction product of the combustible particles, which ceramic article is comprised of a coherent refractory material and has a shape which conforms to that of the of the metal former;
- and
- e. separating the metal former from the ceramic article, which separation is facilitated by the pre-coating of the metal former with the refractory cement which becomes brittle as a result of the heat applied to it during projection so as to facilitate the removal of the ceramic article from the metal former.
A process for making a ceramic article, comprising:
- a. providing a powder mixture comprised of refractory particles and combustible particles which react exothermically;
- b. heating a metal former to a temperature of at least 850.degree. C.;
- c. projecting the powder mixture against the metal former in the presence of an oxygen-rich gas so that the combustible particles react exothermically and produce a ceramic article on the metal former from the refractory particles and the reaction product of the combustible particles, which ceramic article is comprised of a coherent refractory material and has a shape which conforms to that of the metal former;
- and
- d. separating the metal former from the ceramic article, wherein the ceramic article is a tubular article which is removed from the metal former as it is being formed.
An apparatus for making a ceramic article, comprising:
- projection means for projecting a powder mixture comprised of refractory particles and combustible particles;
- supply means for an oxygen-rich gas;
- and
- a metal former made of a material which is resistant to high temperature and to chemical attack, against which the projected powder mixture can react with the oxygen-rich gas in use to produce a ceramic article on the metal former from the refractory particles and the reaction product of the combustible particles, which ceramic article is comprised of a coherent refractory material and has a shape which conforms to that of the metal former from the refractory particles and the reaction product of the combustible particles,
- wherein the metal former has a surface which is free from any indentations or projections which would tend to assist formation of a bond between the coherent refractory material and the metal former.
Dependencies are inferred from the claim text.