A mean-field micromechanical model of thermal-ratcheting behavior in short fiber-reinforced metal matrix composites

Thermal-ratcheting behavior in short fiber-reinforced metal matrix composites has been investigated. The internal stresses due to mismatch in thermal expansion coefficients between the fiber and matrix in the composites can introduce anomalous deformation under thermal-cycling conditions with or without external mechanical loads. This study has resulted in a more comprehensive understanding of such thermal-ratcheting behavior in short fiber-reinforced composites subject to a wide range of external uniaxial loads based on a mean-field micromechanical model considering the local mass transfer by diffusion along the fiber–matrix interface. The validity of the model has been verified through systematic experiments with directionally solidified Al–Al3Ni eutectic composites.