Abstract: There is disclosed a raw composition, as well as a fired shape, known in the art as a clay-bonded graphite crucible for melting metals, which contains a quantity of fused silica and is particularly adaptable to melting metals in high-energy, induction furnaces.

Abstract: Cracking of large monolithic cordierite segments and in particular monolithic honeycombed substrates having a matrix of thin walls forming a multiplicity of open ended cells extending from one end of the substrate to the other end is reduced or eliminated by limiting the amount of raw clay used in formulating the clay-talc-alumina raw material batch. The raw clay may be eliminated entirely but is preferably at least 10% of the whole batch and not more than 31% of the whole batch with the balance of the clay constituent to the raw material batch being calcined clay. The raw material batch is preferably formulated to yield at least 90% cordierite phase upon reaction during sintering.