Basal Dislocation Mobility in Zinc Single Crystals
Basal Dislocation Mobility in Zinc Single Crystals
复制标题
锌单晶中的基本位错迁移率
DOI：
10.1063/1.1656907
复制
发表时间：
1967
影响因子：
3.2
通讯作者：
K. Adams
中科院分区：
文献类型：
--
作者：
K. Adams
对99.999%纯锌单晶进行了基面位错迁移率和流动应力应变率敏感性的实验测量。在[1210](0001)基面滑移系统中，通过观察控制幅度和持续时间的载荷脉冲产生的滑移带生长，测量了位错的迁移率。位错的局部重排发生在7磅/英寸的分辨应力下。滑移带在大于7磅/英寸的应力下形成，其生长速度在7-12磅/英寸的剪应力范围内为7-80厘米/秒。应变率灵敏度和迁移率测量的比较表明，运动位错密度的显著变化与应变率的变化有关。密度的这种变化通常被之前的调查人员忽视了。提出了位错模型来解释观察到的应变率敏感性。
Experimental measurements of basal dislocation mobility and the strain-rate sensitivity of the flow stress have been made on 99.999% pure zinc single crystals. Dislocation mobility in the [1210] (0001) basal slip system was measured by observing slip band growth produced by load pulses of controlled amplitude and duration. Local rearrangement of dislocations occurs at a resolved stress of 7 lb./in.^2. Slip bands are formed at stresses greater than 7 lb./in.^2, and their growth velocities are in the range of 7 to 80 cm/sec for shear stresses between 7 and 12 lb./in.^2. The results of the experimental measurements of dislocation mobility are discussed in relation to current theories. A comparison of the strain-rate sensitivity and the mobility measurements shows that a significant change in the density of moving dislocations is associated with a change in strain-rate. This change in density has generally been ignored by previous investigators. A dislocation model is proposed to explain the observed strain-rate sensitivity.