High-temperature plasticity in copper polycrystals
High-temperature plasticity in copper polycrystals
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发表时间：
1991
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通讯作者：
S. Chen;U. F. Kocks
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作者：
S. Chen;U. F. Kocks
描述了一种测试和分析程序，该程序可消除在高温和足够高的应变速率下使扩散成为不重要机制的材料变形参数。作为第一步，一个简单的缩放过程中使用的连续应力应变曲线，以减少数据基本上是一条曲线，微分，归一化硬化图。然后在微观水平上假设了一种独特的这种曲线：它反映了通过位错储存和重排的硬化和动态恢复机制。它可以集成为任意应变路径;初始纹理和纹理变化可以在这一步中合并;它们可能会影响宏观行为。用热激活理论可以很好地处理标度参数与温度和应变速率的关系。它允许将温度和应变率压缩成单个组合和归一化变量，然后可以针对归一化应力绘制该变量。该简化图上的行为不一定遵循简单的公式，但它是唯一的，并且允许通过简化图上的插值来外推到测量范围之外的温度和应变率。本文给出了纯铜多晶形变的新数据。参考文献11篇，图7。«少
A procedure for testing and analysis is described that elicits the material parameters for deformation at elevated temperatures and at strain rates high enough to make diffusion an unimportant mechanism. As a first step, a simple scaling procedure is used on continuous stress strain curves to reduce the data to essentially one curve; the differentiated, normalized hardening diagram. A unique curve of this kind is then assumed at the microscopic level: it reflects the mechanism of hardening and dynamic recovery through dislocation storage and rearrangement. It can be integrated for arbitrary straining paths; initial texture and texture changes can be incorporated at this step; they may affect macroscopic behavior substantially. The dependence of the scaling parameters on temperature and strain rate can be well treated by thermal activation theory. It allows a condensation of temperature and strain rate into a single combined and normalized variable which may then be plotted against a normalized stress. The behavior on this reduced diagram does not necessarily obey a simple formula, but is is unique and allows extrapolation to temperatures and strain rates outside the range of measurements by interpolation on the reduced diagram. New data are presented for the deformation of pure coppermore » polycrystals. 11 refs., 7 figs.« less