It was shown that, in the case of the magnesium matrix, interface thermal stresses were relaxed by dislocation motion. Moreover the results obtained by mechanical spectroscopy prove that this dislocation motion was controlled by a solid friction mechanism, which was not thermally activated. This point was very interesting for the development of MMCs, which exhibit a high damping capacity over a wide frequency range. Dislocation hysteretic motion in the magnesium matrix was evidenced by the dependence of the mechanical loss on the stress amplitude. The obtained relationship obeys perfectly to the Granato–Lücke model for dislocation breakaway.

Thermal Stress Relaxation in Magnesium Matrix Composites Controlled by Dislocation Breakaway. A.S.M.F.Chowdhury, D.Mari, R.Schaller: Composites Science and Technology, 2010, 70[1], 136-42