Hall-Petch effect and strain gradient effect in the torsion of thin gold wires

摘要

Gold wires with diameters of 20 and 50 μm were annealed in the temperature range 330-750℃ to obtain different grain sizes. Torsion and tension experiments on these wires confirm that the Hall-Petch effect is stronger than the strain gradient effect in the small grain size region (below 5μm). With the grain size becomes larger, the strain gradient effect is evident. We find that these two mechanisms are synergistic, and this interaction strongly depends upon the grain size.