Diffusional/plastic relaxation of internal stress in giant-magnetostriction particle reinforced metal-matrix composite

A giant-magnetostriction particle reinforced tin-matrix composite, Sn/Terfenol-D, was fabricated, and the relaxation behavior of internal stress caused by magnetostriction of the particles was directly observed as an average strain change of the composite with and without an external stress. The diffusional relaxation under zero external stress was not observed. During steady-state creep, the internal stress by magnetostriction suppressed dislocation movement and removal of the magnetostriction activated the dislocation movement. This implies that the plastic relaxation of internal stress was observed directly from the average strain change.