Ultrahigh damping capacity achieved by modulating R phase in Ti49.2Ni50.8 shape memory alloy wires

An ultrahigh damping capacity with internal friction close to 0.35 was detected over a large temperature range of 75 °C (from -40 to 35 °C) in Ti49.2Ni50.8 shape memory wires by adjusting the B2→R phase transformation through a low-temperature aging treatment. Microstructural analysis showed that the excellent damping performance is attributed to high-density nanodomains in the R phase, which are induced by short-range Ni segregation. These results are expected to further expand capacity for designing damping microstructure.