Effect of Solute-Dislocation Interactions on the Deformation Behavior of Al-Mg and Fe-C Solid Solutions

摘要

The effect of solute-dislocation interactions on the deformation behavior of a fcc substitutional solid solution, Al-0.8% Mg alloy, and a bcc interstitial solid solution, Ferrovac-E iron, was investigated by load relaxation tests supplemented with constant displacement-rate tests at temperatures corresponding to a high- and low-homologous temperature of these metals respectively. Hart's state variable formulation was used to analyze the deformation behavior. The mechanical states of both the Al-0.8% Mg alloy and the Ferrovac-E iron are influenced by solute-dislocation interactions during the load relaxation process. Over a sufficiently wide strain rate range, the load relaxation data in the form of log stress vs log strain rate plots can be divided into three regions, a fast state and a slow state with a transient state connecting them. The load relaxation data of the fast and slow states can be represented adequately by Hart's State Variable formulation. Strong solute-dislocation interactions are involved in the transient state, as indicated by the highly serrated flow observed in a constant displacement-rate test with the strain rate in the transient state. 69 refs., 31 figs., 7 tabs.