Results of Preliminary Experiments on the Plasticity of Ice Crystals
Results of Preliminary Experiments on the Plasticity of Ice Crystals
复制标题
冰晶可塑性的初步实验结果
DOI：
10.3189/002214354793702533
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发表时间：
1954
影响因子：
3.4
通讯作者：
S. Steinemann
中科院分区：
文献类型：
--
作者：
S. Steinemann
为了研究冰的可塑性，必须小心地生长冰的单晶，因为它很容易产生令人不安的谱系结构。样品的方向可以从生长图（树突）和廷德尔的“花”中找到;这些给出了a轴，因为两种情况下的分支都指向[1120]方向。滑移发生在基面上，没有确定的滑移方向。在纯剪切中，存在两个蠕变阶段，第一阶段是未变形晶体中10%~ 20%的滑移，第二阶段是剪切力越大，蠕变速度越高。这两个阶段都遵守定律，第一种情况下n为2.3-4，第二种情况下n为1.3-1.8。在纯剪切条件下，相变点以上的变形状态保持稳定，不发生再结晶。通过再结晶恢复未变形状态仅发生在不均匀变形的零件中。这一观测结果可能会对解释冰川运动的测量结果和实验室中多晶样品的测试产生影响。
Abstract The growth of single crystals of ice for the study of plasticity has to be done with care, since a disturbing lineage structure is easily generated. The orientation of specimens can be found from growth figures (dendrites) and Tyndall’s “flowers”; these give the a-axis, as the branches in both cases point in the [1120] direction. Slip occurs on the basal plane without following a definite glide direction. In pure shear two stages of creep exist, the first for a glide of 10–20 per cent in an undeformed crystal, the second for greater shears having a higher creep velocity. Both stages obey the law , n being 2.3–4 in the first case and 1.3–1.8 in the second. The deformed state above the transition remains stable and no recrystallization takes place in pure shear. Restoration of the undeformed state by recrystallization occurs only in inhomogeneously deformed parts. This observation may have an influence in interpreting measurements of glacier movements and tests on polycrystalline specimens in the laboratory.