Investigation of phase transition, mechanical properties, and damping behavior of NiTip/6061Al laminar composites

Abstract

The microstructure, phase composition, phase transition process, mechanical properties, and damping behavior of NiTip/6061Al laminar composites were investigated by introducing a NiTi particle layer with phase transition characteristics into the 6061 aluminum matrix using rolling composite technology. No defects, such as cracks or holes, were found in the NiTi particle layer, and no agglomeration of the NiTi particles was recorded. The interlayer interface between the alloy particle layer and the 6061Al matrix was clear and well-combined, and no new phase formation occurred in the composite. The composites exhibited phase transition characteristics similar to NiTi alloy particles, and the phase transformation temperature of the composites increased gradually with an extended aging time of the NiTi-reinforced particles. Following aging strengthening, the NiTip/6061Al laminar composites demonstrated higher yield strength than the 6061-T6 aluminum alloy, while their tensile strength remained similar. Pre-aging treatment of the NiTi particles had only a minor effect on the mechanical properties of the composites. The damping capacity of the laminar composites surpassed that of the 6061-T6 aluminum alloy due to the synergistic enhancement of phase transition damping from the NiTi particles and interparticle interface damping within the particle layer The internal friction values of the NiTip/6061Al laminar composites at 60 °C and 350 °C were up to 0.0134 and 0.1146, respectively, which were 211% and 313% higher than those of the 6061-T6 aluminum alloy at the corresponding temperature. The storage modulus and the comprehensive damping performance (EIF) of the NiTip/6061Al laminar composites were higher than those of the 6061-T6 aluminum alloy.