PLASTIC DEFORMATION OF NICKEL SINGLE CRYSTALS AT LOW TEMPERATURES
PLASTIC DEFORMATION OF NICKEL SINGLE CRYSTALS AT LOW TEMPERATURES
复制标题
DOI：
10.1080/14786435808236826
复制
发表时间：
1958-01-01
影响因子：
1.6
通讯作者：
HAASEN, P
中科院分区：
文献类型：
--
作者：
HAASEN, P
镍单晶（纯度99.98%和99.4%）在4.2°K和300°K之间的不同温度下拉伸变形。确定了剪切应力-剪切应变关系以及流变应力随温度的可逆变化。获得的加工硬化参数进行了讨论的位错理论，主要是在Al和Cu的数据的基础上开发的。根据动态回复开始时应力的温度依赖性，估算出交叉滑移的激活能略低于铜的激活能，意味着层错能略高，并从理论上分析了变温法与加工硬化参数之间的关系，指出了变温法研究流动应力的优越性。目前镍的实验结果证实了这一关系。尽管没有观察到铜中所发现的那种载荷下降，但在4.2°K和20°K下获得的金相和X射线证据支持镍中的形变孪晶。记录的载荷-延伸曲线中的锯齿表明在最低温度下的不连续流动。
Single crystals of nickel (purities 99.98% and 99.4%) have been deformed in tension at various temperatures between 4.2°K and 300°K. Shear stress-shear strain relations have been determined as well as the reversible change of flow stress with temperature. The work-hardening parameters obtained are discussed in terms of dislocation theory that has been developed mainly on the basis of data on Al and Cu. From the temperature dependence of the stress at the beginning of dynamical recovery the activation energy of cross-slip is estimated to be slightly lower than that of copper, implying a somewhat higher stacking fault energy.The advantages of the temperature change method for an investigation of the flow stress are pointed out following a theoretical analysis of the relation between this method and that of the work-hardening parameters. The present results on nickel confirm this relation.Metallographic and x-ray evidence has been obtained in favour of deformation twinning in nickel at 4.2°K and 20°K although no drop in load has been observed of the kind found in copper. Serrations in the recorded load-extension curves indicate discontinuous flow at the lowest temperatures.