Precipitate-induced plastic anisotropy: Explicit solutions of the plastic anisotropy due to plate-shaped precipitates
Precipitate-induced plastic anisotropy: Explicit solutions of the plastic anisotropy due to plate-shaped precipitates
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DOI：
10.1007/s11661-999-0277-4
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发表时间：
1999-05
期刊：
影响因子：
--
通讯作者：
M. Lyttle;J. Wert
中科院分区：
文献类型：
--
作者：
M. Lyttle;J. Wert
在某些铝合金中，观察到的塑性各向异性不能仅通过测量的泰勒因子变化来解释。定性地，有人认为这种差异是由于板状析出物的二次效应造成的。先前已经提出了解决塑性变形和弹性变形沉淀物影响的模型。在本文中，针对板状析出物的情况提出了各向异性强化增量的显式解。这些解决方案可以定量考虑沉淀物对不同习惯平面的影响以及应力老化造成的影响。一般来说，在面心立方材料中，{100}习性平面上的析出物预计可以最大限度地减少由于纹理引起的各向异性；预测 {111} 习惯平面上的沉淀物会加剧由于纹理引起的各向异性；预计其他习惯平面上的沉淀物会产生较小的影响，这是由于对大量晶体学上等效的习惯平面进行平均而产生的。预计改变单一析出物类型的相对取向分布的应力时效只会产生塑性各向异性的轻微变化。当应力时效改变不同习性平面上两种沉淀类型的相对体积分数时，将会观察到对产率变化的更大影响。
In some aluminum alloys, the observed plastic anisotropy cannot be explained solely by the measured Taylor factor variation. Qualitatively, it has been suggested that this difference results from a secondary effect due to plate-shaped precipitates. Models addressing the effect of plastically-deforming and elastically-deforming precipitates have been previously proposed. In the present article, explicit solutions of the anisotropic strengthening increment are presented for the case of plate-shaped precipitates. These solutions allow a quantitative consideration of the effect of precipitates on different habit planes and of the effect due to stress aging. Generally, in fcc materials, precipitates on {100} habit planes are predicted to minimize the anisotropy due to texture; precipitates on {111} habit planes are predicted to accentuate the anisotropy due to texture; and precipitates on other habit planes are predicted to produce a minor effect resulting from an averaging over a greater number of crystallographcally equivalent habit planes. Stress aging to alter the relative orientation distribution of a single precipitate type is predicted to produce only slight changes in the plastic anisotropy. Larger effects on the yield variation will be observed when stress aging alters the relative volume fractions of two precipitate types on different habit planes.