Study of the heat affected zone within metals joined by using reactive multilayered aluminum–nickel nanofoils

The combustive feature of reactive multilayered nanofoils can be harnessed to produce lightweight components in multi-material design. However, the intended use of nanofoils serving as a heat source requires the knowledge of the shape and the depth of the heat affected zone (HAZ) within the joining partners in order to prevent any material damage. This study addresses the experimental and numerical investigation of the HAZ within metallic joints produced by reactive aluminum–nickel nanofoils with varying layer structures. For the first time, the HAZ within reactively joined materials was metrologically quantified due to the use of a specific low-melting alloy. Furthermore, a new modeling approach was developed in order to compute the transient temperature field within the joining partners during and after the exothermic reaction of the ignited nanofoil. The simulation model was validated by using the experimental findings of the HAZ. The review of the predictive accuracy confirmed a good agreement with the experimental data.