Thermomechanical behavior of TiPd-based SMA reinforced Ti matrix smart composites

Two kinds of composites, Ti and Ti-2at.%Cu composites reinforced by a TiPd-based shape memory alloy (SMA) containing 22at.%Pd, 27at.%Ni and 1at.%W, were fabricated by sheath-rolling of SMA fibers which were alternatively laminated with matrix plates. Thermomechanical behaviors of the composites fabricated were investigated experimentally and analytically The 0.5% offset stresses of both composites increased gradually with increasing temperature at temperatures higher than A(f)(0). This stress increase is mainly caused by changes in residual compressive stress in the matrix. The change of this residual stress is associated with the martensite-to-austenite transformation of TiPd-based SMA fibers during loading. The 0.5% offset stresses were calculated by a one-dimensional analytical model and the predictions are in good agreement with the experimental results.