Structural characterization and mechanical properties of rotary melting furnace processed aluminium alloyed ductile irons

The microstructural characteristics and mechanical properties of rotary melting furnace processed aluminium alloyed ductile irons were investigated in this study. This was aimed at developing high performance - low material and processing cost ductile irons, suitable for the production of automobile components. Different compositions of the alloys were processed containing 1-4 wt.% aluminium. X-ray diffractometry, optical, scanning electron microscopy and mechanical properties measurements, were used to characterize the alloys. The results show that the ductile irons consists essentially, nodular and vermicular graphite-type distributed in a predominantly pearlite - ferrite matrix structures which attest to the viability of rotary furnace melt processing for ductile iron production. The nodule count were observed to increase with increase in Al wt.% but nodule sizes and degree of sphericity decreased with increase in Al wt.%. The mechanical properties of the ductile irons increased with increase in Al wt.%, except the ductility which decreased slightly with increase in Al wt.%.