抄録
Single crystals of several low-index orientations were deformed in tension between −195 and 800°C, where the strain-rate was repeatedly changed by a factor of 10. The deformation behaviour showed diverse characteristics at different temperatures and strains. The results were discussed in relation to the pinning and dragging of solute atoms for dislocation motion. The main conclusions are as follows: At −195°C the pinning effect is almost negligible. At 22°C the difference in steady flow stresses at different strain rates was very small at high strain, which suggests that the mobile dislocation density decreased at lower strain rate by the pinning of dislocations. At 200°C the changes in flow stress decreased rapidly to zero at low strain by the pinning of dislocations. At 400°C large load drops appeared after the strain-rate decreases at high strains, which is caused by the appearance of dragging motion of dislocations. Above 600°C the large strain-rate sensitivity of flow stress is controlled by solute atom dragging of dislocations.
