Influence of different concentrations of silicon, copper and tin in the microstructure and in the mechanical properties of compacted graphite iron

Abstract

In this paper the production and characterization of compacted graphite iron alloys in ten chemical compositions is presented. The specimens were obtained through a foundry process performed by a gating system model developed in order to allow the incorporation of silicon, copper and tin. Hardness and tensile tests were performed, as well as microstructural evaluation. Additionally, the results related to the experimental investigation were compared to those obtained from a finite element method analysis. The results showed a correlation between the addition of silicon and the increase of ferrite and graphite count per mm2. Regarding copper and tin additions, the percentage increase of pearlite was associated with the reduction of graphite average size. Changes in chemical composition led to different values of ultimate tensile strength, yield strength and hardness, whose magnitude was mainly related to the amount of ferrite. Computer simulation was considered efficient in predicting these results.