Microstructural Evolution during Continuous Heating of Multilayered Al/Fe Metallic Composite Processed by Accumulative Roll Bonding
Résumé
Despite the large number of studies on the development of multilayered composites using accumulative roll
bonding method (ARB), there are not enough available details concerning the effect of the temperature
variation on the constituent layer microstructure and the nature and kinetics of the developed intermetallic
compounds. The present work aims to process an Al/IF steel multilayered composite using ARB and to
understand the effect of non-isothermal heating on its structural evolution. The elaborated material is
characterized by using thermal Differential Dilatometry (DD), Scanning Electronic Microscopy (SEM) and
x-ray Diffraction (XRD). The progress of the ARB leads to the dispersion of the Fe layers between the Al
layers and does not lead to the formation of diffusion layer. The continuous heating leads, for temperature
lower than 330 °C, to the occurrence of the recovery reaction in the Al layers, which produces a big
contraction and causes a partial softening of the material. The formation of the intermetallic compound
Al5 Fe2 seems to occur at higher temperatures and leads to a significant expansion of the material. This
effect is explained by the increase in the atomic specific volume.