Abstract:
With the development of industrial technology, the field of mechanical engineering has put forward higher requirements for the vibration and noise reduction of aluminum alloy materials. In order to solve the problem of low intrinsic damping of aluminum alloy, NiTip/5052 Al composites with phase transformation damping characteristics were prepared by friction stir processing (FSP). The microstructure and phase composition of NiTip/5052 Al composites were analyzed by SEM, EDS and XRD. The phase transformation processes, mechanical properties and damping behaviors of the composites were analyzed by differential scanning calorimetry (DSC), universal testing machine and dynamic mechanical analysis (DMA), respectively. The results show that the interfaces between NiTi particles and 5052 Al matrix are well bonded after FSP, and no interfacial reaction occurs. The NiTip/5052 Al composites have martensitic transformation characteristics of NiTi alloy. The strength of NiTip/5052 Al composites are higher than 5052 Al and FSP-5052 Al alloy. The tensile strength of as-NiTip/5052 Al composite is 240 MPa, which is 23.7% and 10.1% higher than 5052 Al and FSP-5052 Al alloy, respectively. The damping properties of NiTip/5052 Al composites are significantly better than 5052 Al alloy and FSP-5052 Al alloy, and the composites exhibit significant phase transformation internal friction peaks. When the temperature rises to 23℃, the internal friction peak of 550℃-NiTip/5052 Al composite is 300% and 140% higher than 5052 Al and FSP-5052 Al alloys, respectively. When the temperature rises to 33℃, the internal friction peak of as-NiTip/5052 Al composite is 233% and 100% higher than 5052 Al and FSP-5052 Al alloys, respectively. The storage modulus of NiTip/5052 Al composites decrease with increasing temperature and strain, and their storage modulus are higher than 5052 Al alloy and FSP-5052 Al alloy.