Dynamic internal friction of mono-crystalline aluminum during constant rate deformation at high temperatures

Abstract

Dynamic internal friction measured during mechanical testing is a useful tool to study the microscopic process of plastic deformation. Recently, the authors have investigated the dynamic internal friction of mono-crystalline pure aluminum during creep at temperatures around 0.5 Tm (Tm is the melting point). In the present paper, they extend the research to the case of constant rate deformation at high temperatures. The constant rate deformation is different from creep in that for the former, the strain rate is kept constant and the flow stress is changed with time (or strain); while for the latter, the applied stress (or load) is kept constant and the strain rate is changed with time (or strain). It will be shown that the behavior of dynamic internal friction during constant rate deformation can also be interpreted with the model described in the previous paper, and the generation rate of dislocations during deformation can be evaluated from the internal friction as well.