this invention provides a hard , strong ceramic body and method of manufacture whereby the body , after being formed into the desired shape and size can then be fired into a monolithic structure without any shrinkage or distortion during the firing operation . the &# 34 ; green ,&# 34 ; unfired ceramic composition comprises one or more powdered refractories and one or more powdered glasses which have a melting point below the softening point of the selected refractory material . preferred refractories are alumina and zirconia ; preferred glasses are lead borosilicate and barium borosilicate . the composition may also contain a metal powder .