The dense, fine grain structure of Meehanite® metal which assures casting solidity and consistent physical properties relate the carbide stability of the molten metal, both before and after processing to the casting section. These controls which are the basis of a series of patents dating back to 1926 are fundamental to the Meehanite® process and are the primary reasons for the structural integrity exhibited by Meehanite® castings.
1. The Meehanite® Process involves a number of patented features seeking to control and produce the desired graphite distribution and the desired matrix structure in the casting. It requires very careful selection of raw materials, meticulous process controls and a very thorough knowledge of the foundry industry of cast iron.
2. The Meehanite® Process utilizes standard procedures in all phases of casting manufacture, including gating and rise ring techniques, sand control testing methods and many specialized molding procedures. It eliminates the guesswork, thereby resulting in an engineering product of high quality and reliability.
3. More recently, the Meehanite® Process has advanced to cover the manufacture of high strength austenitic ductile iron –MEEHANITE® ADI.
Expressed in its simplest form, Meehanite® metal is first melted to a definite degree of undercooling or constitution which is related to the section of the casting to be poured and the range of physical properties such as tensile strength and hardness required. Nucleation with patented mixtures of graphitizing agents results in the removal of undercooling, in the controlled precipitation of graphite and in a fine grained eutectic cell structure which determines the density and physical integrity of the casting. Ordinary cast irons made to chemical specifications which do not include the benefit of controlled undercooling are influenced by mass effect to a maximum degree and for this and other reasons cannot be considered an equivalent to Meehanite® metal.