Achieving high-damping NiTip/7075Al composites with controllable phase transformation behavior fabricated by friction stir processing

To achieve controllable damping temperature zones in aluminum matrix composites, the NiTip/7075Al composites with controllable phase transformation characteristics were prepared through friction stir processing (FSP) and heat treatment. Aging of NiTi particles led to a downward shift in the phase-transition peak temperature of the composite, accompanied by a sharper peak. During the cooling process, the as-NiTip/7075Al + T6 composites underwent a B2 -> R transformation and an R -> B19' transformation. Furthermore, the T6 treatment effectively enhanced the tensile strength of the composites. The damping properties of NiTip/7075Al composites at low-temperatures (<90(degrees) C) were significantly superior to those of FSP-7075Al alloy. The as-NiTip/ 7075Al + T6 composites exhibited two internal friction peaks during cooling, which were 153 % and 211 % higher, respectively, than those observed in the FSP-7075Al alloy at corresponding temperatures. The damping temperature range of the composites can be effectively controlled through T6 treatment and NiTi particle preaging.