Abstract
Internal friction of TiNi wires/epoxy composites were investigated by dynamic mechanical analysis (DMA) in this study. TiNi wires/epoxy composite and neat epoxy both show significant Tg transition peaks with tan δ above 0.40 at around Tg temperature and lower internal friction peaks with tan δ below 0.06 at around -40 °C. The internal friction peaks at lower temperature is attributed to the crankshaft motion of the glyceryl-like groups in diglycidyl ether of bisphenol A. TiNi wires/epoxy composite also possesses two B19'→R and R→B2 martensitic transformation internal friction peaks at around room temperature with tan δ about 0.04 The peak temperatures of the Tg transition and the low temperature peaks of the TiNi wires/epoxy composites increases with the increase of applied frequency and their activation energies are calculated as 419.1 and 48.7 kJ/mole, respectively. Embedding TiNi wires into epoxy matrix can enhance the Young's modulus and ultimate strength of the composite.