Additivity of strengthening mechanisms in ultrafine grained Al-Mg-Sc alloy
Additivity of strengthening mechanisms in ultrafine grained Al-Mg-Sc alloy
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DOI：
10.1016/j.msea.2013.05.006
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发表时间：
2013-09-15
期刊：
影响因子：
6.4
通讯作者：
Mishra, R. S.
中科院分区：
文献类型：
--
作者：
Kumar, N.;Mishra, R. S.
针对超细晶Al-Mg-Sc合金的特殊性能，研究了超细晶Al-Mg-Sc合金屈服强度的预测方法。采用搅拌摩擦工艺制备了超细粉末。利用电子背散射衍射和透射电子显微镜对晶粒尺寸、位错和纳米Al-3（Sc，Zr）颗粒的微观结构进行了表征。Peierls-Nabarro应力，固溶强化，沉淀强化，晶界强化，位错强化的贡献进行了评估，使用现有的强化模型。根据合金的微观组织状态，选择了可加性定律来预测合金的屈服强度。粗晶和UFG合金的组织状态有利于使用线性加和规则比勾股定理。还使用混合（线性和毕达哥拉斯）加和性规则来评估其YS预测能力。UFG合金的预测和实验获得的YS之间观察到33-55%的范围内的差异。其原因与晶界强化模型的预测过高有关。HP斜率小于正常斜率值能够更接近地预测UFG合金的YS。(C)2013爱思唯尔有限公司版权所有。
In the light of unique and anomalous properties of ultrafine grained (UFG) alloys, an effort was made to develop a predictive capability of the yield strength (YS) of UFG Al-Mg-Sc alloy. UFG microstructure was introduced using friction stir processing. Microstructural characterization of grain size, dislocations, and nano-sized Al-3(Sc,Zr) particles was carried out using electron backscatter diffraction and transmission electron microscope. The contribution from Peierls-Nabarro stress, solid solution strengthening, precipitation strengthening, grain boundary strengthening, and dislocation strengthening were assessed using existing strengthening models. Additivity law to predict the YS of the alloy was chosen based on the microstructural state of the alloy. The microstructural state of coarse grained and UFG alloy favored the use of linear additivity rule over Pythagorean. The use of a mixed (linear and Pythagorean) additivity rule was also carried out to assess its YS prediction capability. A difference in the range of 33-55% was observed between predicted and experimentally obtained YS for UFG alloy. The reason was related to the overprediction from grain boundary strengthening model. A smaller HP slope than the normal slope value was able to predict the YS of the UFG alloy more closely. (C) 2013 Elsevier B.V. All rights reserved.