Dynamic internal friction of mono-crystalline aluminum during high temperature creep

Abstract

Dynamic internal friction of mono-crystalline pure aluminum has been investigated during creep at temperatures around 0.5 T m. A pronounced peak of internal friction versus creep time (Q −1-t peak) appears in the latter part of primary creep. The internal friction exhibits an anomalous amplitude dependence effect, i.e., it increases as the strain amplitude decreases. The peak height increases linearly with a decrease of frequency. The effect of creep stress and creep temperature has also been investigated. TEM observations show that the variation of dynamic internal friction is closely associated with the variation of dislocation configuration.