Effects of aluminium addition and austempering temperatures on Al-alloyed ductile iron microstructure and mechanical properties

The research investigates the effect of varying amounts aluminium (1.05, 1.575, 2.29, 3.02 and 3.74 wt.%) addition heat treatment (austempering at 300, 350, 400 oC) on microstructure mechanical properties ductile cast iron alloys. graphitizing effects Al alloy varied austempering temperatures hardness, tensile strength, impact toughness (DCI) were evaluated. results influences DCI determined presented as graphical data while microstructures done by using a scanning electron microscope (SEM). revealed that into matrix brings about precipitation ferrite around graphite nodules. combined increase content produced greater hardness values Al-alloyed samples than as-cast sample. value for entire sample ranged between 27.25 to 57.03 BHN. Tensile strength increased with an in lower temperatures, whereas, higher temperature.