Manufacture of monolithic, stiff, lightweight ceramic articles

A method of manufacturing a light-weight yet sturdy ceramic article, comprising the steps of

• forming at least one fugitive core including a main portion and at least one holding portion projecting from the main portion;
• positioning the fugitive core in a mold cavity bounded by a multitude of bounding surfaces so that the holding portion holds the main portion at predetermined spacings from all of the bounding surfaces;
• filling the mold cavity around the fugitive core with a dense slip constituted of ceramic or metal particles in a mixture with a liquid medium to form a ceramic or metal preform embedding the fugitive core in its interior;
• freezing the ceramic or metal preform;
• causing the fugitive core to dissolve and escape from the interior of the frozen ceramic or metal preform, including contacting the fugitive core with a chemical agent that dissolves the material of the fugitive core;
• controlling the temperature of at least the chemical agent so as to be substantially equal to that of the frozen ceramic or metal preform just prior to said contacting;
• and
• converting the ceramic or metal preform into the ceramic or metal article.