Self-propagation Combustion Behavior with Varying Al/Ni Ratios in Compression-Bonded Ni-sputtered Al Foil Multilayers

Compression-bonded Ni-sputtered Al foil multilayers with various atomic ratios of Al/Ni are fabricated with various bilayer thicknesses. The microstructures that are formed after the self-propagating combustion using laser ignition result in equilibrium phases in the Al/Ni binary system. Homogeneous intermetallic compounds for Al3Ni2 and AlNi are obtained for the first time in the micrometer-scale multilayers through controlling the Ni layer thickness. The onset temperatures of the multilayers are below 800 K (527 °C) for all multilayer samples. The maximum temperatures correspond to the liquidus temperatures of the intermetallic compounds. The self-propagating direction is divided into a transverse propagating direction and a gross propagating direction. The measured gross propagation velocities vary widely without exhibiting a clear trend. However, the transverse propagation velocity is dependent on the measured maximum temperatures, while the effects of the bilayer thickness are not discernible. The measured transverse propagation velocities are similar to the reported propagation velocities for sputtered multilayers with similar bilayer thicknesses.