Some observations of grain boundary ledges and ledges as dislocation sources in metals and alloys
Some observations of grain boundary ledges and ledges as dislocation sources in metals and alloys
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DOI：
10.1007/bf02658408
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发表时间：
1975-02
期刊：
影响因子：
--
通讯作者：
L. Murr
中科院分区：
文献类型：
--
作者：
L. Murr
用透射电子显微镜直接观察了退火态Ni、Al、Cu、Mo、Ta、Ir、304不锈钢和Inconel 600中的晶界台阶。已经观察到晶界壁架是塑性变形期间和之后的位错源，并且类似于透射电子显微镜中的位错堆积的外观。在Ni和304不锈钢中观察到凸台密度（每单位晶界长度的数量）随着晶界取向差的增加而增加，并且在1060°C的退火温度下观察到在0度<θ<90度的范围内取向差的分布是连续的。还观察到304不锈钢中的平均晶界取向差随着冷轧后恢复温度的降低而降低，并且在660 ° C至1060°C的温度范围内从10 °至45 °变化。本研究的一个要点是，李的理论处理的流动应力，晶粒尺寸的关系的基础上存在的晶界壁架和它们的行动作为应力下的位错源被证明是正确的。
Direct observations of grain boundary ledges have been made in annealed Ni, Al, Cu, Mo, Ta, Ir, 304 Stainless Steel and Inconel 600 by transmission electron microscopy. Grain boundary ledges have been observed to be sources of dislocations during and after plastic deformation, and to resemble the appearance of dislocation pileups in the transmission electron microscope. Ledge density (number per unit length of grain boundary) has been observed to increase with an increase in grain boundary misorientation in Ni and 304 Stainless Steel, and the distribution of misorientations was observed to be continuous over the range 0 deg <θ<90 deg at an annealing temperature of 1060°C. The mean grain boundary misorientation in 304 Stainless Steel was also observed to decrease with a decrease in the recovery temperature following cold reduction and to vary from 10 to 45 deg in the temperature range of 660 to 1060°C. An essential point of this investigation is that Li’s theoretical treatment of the flow-stress, grain-size relation based on the existence of grain boundary ledges and their action as sources of dislocations under stress is shown to be correct.