Combustion Synthesis Reaction Behavior of Cold-Rolled Ni/Al and Ti/Al Multilayers

摘要

A two- or three-stage combustion synthesis reaction process was observed in cold-rolled Ni/Al and Ti/Al multilayer foils. The phase evolution sequence from the two foil types was studied by differential scanning calorimetry (DSC). Several exothermic peaks were identified from the DSC thermograms. Subsequently, the foils were heated to each peak temperature to identify the reaction product associated with each peak. X-ray diffraction and scanning electron microscopy analyses were used to further discern the thermal events, whether they corresponded to intermediate or final reaction products. The Ni/Al foils went through three reaction stages. In the first stage, Al3Ni was formed as the reaction product. During the second stage, the part of the foil underwent thermal explosion. In the last stage, the heat released by the thermal explosion triggered a self-propagating high temperature synthesis reaction that resulted in the formation of AlNi. In contrast, the Ti/Al foils experienced only two reaction stages. In the first, the reaction zone propagated across the foil with formation of Al3Ti at the Ti/Al interface. Then, a thermal explosion reaction occurred in the part of foil that was heated, resulting in many different phases.