Temperature and strain rate effects on the strength and ductility of nanostructured copper
Temperature and strain rate effects on the strength and ductility of nanostructured copper
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DOI：
10.1063/1.1618370
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发表时间：
2003-10
影响因子：
4
通讯作者：
Yinmin M Wang;E. Ma
中科院分区：
文献类型：
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作者：
Yinmin M Wang;E. Ma
我们发现，与传统的面心立方金属的温度/速率不敏感的行为相比，具有超细晶粒尺寸的铜的屈服强度变得明显的温度和应变率依赖。热激活变形机制在室温下，特别是在低应变速率下是有效的，但在77 K下不是。除了强度的增加之外，拉伸延展性和特别均匀的应变也在低温温度下并且随着应变速率的增加而增加，这是由于抑制的动态恢复引起的改善的应变硬化的结果。
We show that the yield strength for Cu with ultrafine grain sizes becomes obviously temperature and strain-rate dependent, in contrast to the temperature/rate insensitive behavior of conventional face-centered-cubic metals. A thermally activated deformation mechanism is operative at room temperature and especially at slow strain rates, but not at 77 K. In addition to the gain in strength, the tensile ductility and particularly uniform strains also increase at cryogenic temperatures and with increasing strain rate, as a result of improved strain hardening due to suppressed dynamic recovery.