Method and apparatus for casting articles

A method of casting a plurality of articles, said method comprising the steps of providing a ceramic mold having a plurality of ceramic base sections with flat bottom surfaces, a plurality of ceramic article molds each of which is connected to and extends upwardly from a base section and a ceramic molten metal distribution system fixedly connected to upper end portions of the article molds, said method further including the steps of positioning the bottom surfaces of the base sections in flat abutting engagement with a chill plate, conducting molten metal from the distribution system to cavities in the article molds while maintaining the distribution system fixedly connected with the upper end portions of the article molds, cooling the lower end portions of the article molds and the base sections to a temperature which is lower than the temperature of the distribution system by conducting heat from the article molds and the base sections to the chill plate, and maintaining the bottom surfaces of the base sections in flat abutting engagement with the chill plate by moving one of the base sections relative to another base section under the influence of thermal expansion forces transmitted from the distribution system to the one base section.

A ceramic mold for use in casting a plurality of articles, said mold comprising a plurality of article molds each of which has an article mold cavity with a configuration corresponding to the configuration of one of the articles, molten metal distribution means fixedly connected with upper end portions of the article molds for conducting molten metal to each of the article mold cavities, and a base plate connected with lower end portions of said article molds, said base plate including stress concentration means for defining a plurality of weakened locations spaced from said article molds to promote cracking of the base plate at the weakened locations under the influence of stresses induced in said base plate during the casting of articles.

A ceramic mold for use in casting a plurality of articles, said mold comprising a plurality of article molds each of which has an article mold cavity with a configuration corresponding to the configuration of one of the articles, rigid molten metal distribution means fixedly connected with upper end portions of the article molds for conducting molten metal to each of the article mold cavities, and a rigid base plate connected with lower end portions of said article molds, said base plate including a body of ceramic material and means for cracking said body of ceramic material upon heating of the ceramic mold, said means for cracking said body of ceramic material including expansion material having a coefficient of thermal expansion which is greater than the coefficient of thermal expansion of said body of ceramic material to enable said expansion material to expand to a greater extent than said body of ceramic material upon heating of the mold.

A method of casting a plurality of articles comprising the steps of providing a mold having a ceramic base plate, a plurality of ceramic article molds connected to and extending upwardly from the base plate and a ceramic molten metal distribution system connected to upper end portions of the article molds, said method further including the steps of conducting a flow of molten metal into the distribution system, cracking the base plate at location between the article molds to form a pluraltiy of separate base sections, and moving at least one of the base sections relative to another base section under the influence of forces transmitted from the distribution system to the one base section.