Ferrous Alloys

The Fe-Mn-Al-C lightweight alloys are the new research frontier in the field of structural and automotive materials to meet the ever-increasing necessity of energy efficient engineering systems. The addition of Al in these newer generation alloys not only increases the stacking fault energy (SFE) for better dislocation glide movement but also reduces the density significantly. Based on the estimation of stacking fault energy and thermodynamic phase diagram, the alloy design philosophy is adopted systematically where they are characterised as transformation induced plasticity steel (SFE < 20mJ/m2), twinning induced plasticity steel (~20-40 mJ/m2), and micro-band induced plasticity steel (SFE > 40 mJ/m2). We are basically fascinated to explore the structure-property relationship of this tremendously diverse array of Fe-Mn-Al-C based lightweight steels on the basis of their phase transformation, precipitation, strengthening mechanism, recrystallization phenomenon and texture evolution. In addition, to the inherent properties of the lightweight steels, the high Al  content in this alloy enhances the precipitation of various intermetallic compounds viz., k-carbides, B2 or DO3 precipitates which could seriously influence the thermo-mechanical processing of the alloy. In this regard, we also perform the hot deformation of the high Al containing Fe-Mn-C alloy at various processing conditions and identify the ‘safe’ processing window established on the grounds of processing map, activation energy map, microstructural evolution and deformation mechanism. 

 

​