Internal friction of Ti–Ni–Cu ternary shape memory alloys

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 370; no. 1; pp. 444 - 448
• Main Authors: Yoshida, I., Monma, D., Iino, K., Ono, T., Otsuka, K., Asai, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15-04-2004; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Damping property; Exact sciences and technology; Internal friction; Martensitic transformation; Martensitic transformations; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Other mechanical properties; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; Shape memory alloy; Ti–Ni–Cu; Ti–Ni–Cu; Martensitic transformation; Internal friction; Shape memory alloy; Damping property; Damping; Differential scanning calorimetry; Scanning electron microscopy; Ternary alloy; Electrical conductivity; Precipitate; Solution heat treatment; Precipitation; Thermoelectric power; Titanium; Ti-Ni-Cu; Nickel alloy; Copper alloy
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2003.05.003

Low frequency internal friction was measured on three specimens of Ti–Ni–Cu ternary alloys, the Cu content varying from 10 to 20
at.%, while Ti content was fixed at 50
at.%. The internal friction spectrum consists mainly of two peaks, a sharper one associated with the B2–B19 transformation and the other one at around 250
K, which is much broader and higher than the former. The peak height of the latter is 0.2 for the specimen containing 20% Cu, which shows that this alloy can be an excellent high damping material. Transformation behavior was studied by electrical resistivity, thermopower and DSC measurements, and was compared with the result of internal friction measurements. Solution treatment at higher temperatures lowers the internal friction peak markedly. Scanning electron microscopy observation reveals that the behaviors of precipitates are different for different solution treatment temperature, suggesting that the precipitation behavior is crucial in the damping properties.