The combination of the austempered ductile iron mechanical properties strongly depend on the parameters used on the austempering cycle. On this study, the influence of austempering time and austenitizing temperature on the properties of a ductile iron were evaluated. A metallic bath of Zamak at 380°C was used as an austempering mean. A set of ductile iron blocks were austenitized at 900°C for 90 minutes and submitted to different austempering times in order to determine the best combination of microstructural and mechanical properties. After the definition of the time of austempering, the reduction of the austenitizing temperature was evaluated. The best combination of properties was obtained with austenitizing at 860°C and austempering during 60 minutes.

Due the importance of using commercially Zamak5 in a wide range in industrial applications, however, this study was focused on the enhancing its machining issues by adding pure copper, so the effect of the addition of (1 to 3)% Cu to commercially Zamak5 on its mechanical properties, microhardness, surface texture and corrosion resistance was investigated. A CNC machining tests, microhardness tests, corrosion test, compression test, and microhardness test were performed. It was found that there is an enhancement on the flow stress at 0.2 strain of about 19% for 3% Cu addition followed by 17% and 15% in the case of 2% Cu and 1% Cu respectively. There was an enhancement in microhardness of about 11.6% in the case of 3% Cu addition. The surface finish was improved by increasing the number of copper contents (1 to 3)% to the base material Za5. Polarization measurements revealed that 3% alloy specimen inhibit the corrosion by more than 70% compared with the blank sample.