Effect of alloying elements on structure and mechanical properties of semi-solid processed cast iron

Semi-solid metal processing of alloys is one of the key technologies for producing advanced materials. Through semi-solid processing, it is possible to produce high quality cast components from grey cast iron. A series of experiments were carried out to clarify the effect of the alloying elements copper, chromium, molybdenum, and nickel on the properties of cast iron. A comparison was made of the microstructure and mechanical properties in semi-solid processed cast iron and ordinary cast iron. This showed that an increase in the level of alloying elements in cast iron gave a higher level of hardness. However, the tensile strength of alloyed semi-solid cast iron did not exceed that of grey iron, for every composition, as a result of the characteristic microstructure produced by semi-solid processing. Thus, the alloying elements had little effect on the tensile strength of semi-solid cast iron, but did have an effect on elongation. The tensile strength of semi-solid cast iron, however, still depends on the cooling rate.