The Production Technology of a Modern Material for Heavy Automotive Vehicles - A Compacted Graphite Iron (C.G.I.)

Abstract

The invention of Compacted Graphite Iron and documentation of Compacted Graphite Iron (C.G.I.) were made during pioneering research on production techniques in the late 1940s. They found that when the residual magnesium or cerium content was insufficient to stabilize a fully spheroidal graphite then the intermediate form of graphite is formed which is Compacted Graphite or vermicular appeared in the microstructure. It was up to 1960s that CGI began to be recognized as a modern material combining much of the strength and stiffness of ductile iron with the thermal conductivity and castability of grey cast iron.

Today the result is that where reduced weight and improved performance particularly for automobile cylinder blocks and heads; where mechanical and physical properties of CGI can contribute to meeting the conflicting requirements of weight reduction, improved performance, reduced emissions, recyclability and cost reduction there is tremendous demand for Compacted Graphite Iron to substitute grey iron or ductile iron castings.