摘要：Ice single crystals of various orientations containing various concentrations of H 2 SO 4 up to 11.5 ppm were cut from large pucks of laboratory-grown ice. Constant-strain-rate compression tests were performed on the doped ice crystals both at −20°C at an axial strain rate of 1 × 10 −5 s −1 and at −10°C at 1 × 10 6 s −1 . The stress–strain curves showed a linearly rising stress with increasing strain, followed by a sharply declining stress after reaching a peak. With further strain, the sharp decline in stress slowed. The tests clearly showed, for the first time, that this naturally occurring impurity dramatically decreases both the peak stress and the subsequent flow stress of ice single crystals. The decrease in the peak strength was related to the square root of the concentration of H 2 SO 4 up to 11.5 ppm, suggesting that the solubility limit of H 2 SO 4 in ice is at least 11.5 ppm. The sulfuric acid also appeared to increase the ductility of the ice. Preliminary examination of a doped ice single crystal by synchrotron X-ray topography suggested that sulfuric acid dramatically increases the grown-in dislocation density.
