Quasi-in-situ analysis of dependency of deformation mechanism and work-hardening behavior on texture in Mg-2Zn-0.1Ca alloy
Quasi-in-situ analysis of dependency of deformation mechanism and work-hardening behavior on texture in Mg-2Zn-0.1Ca alloy
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Mg-2Zn-0.1Ca合金变形机制和加工硬化行为对织构依赖性的准原位分析
DOI：
10.1016/j.jallcom.2019.01.159
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发表时间：
2019-05-05
影响因子：
6.2
通讯作者：
Liu, Qing
中科院分区：
文献类型：
--
作者：
Shou, Haoge;Zheng, Jiang;Liu, Qing
通过准原位滑移轨迹分析，研究了晶体织构对Mg-2ZN-0.1Ca合金板材变形机制和加工硬化行为的影响。结果表明，板材的横向(TD)铺展织构减弱。轧制方向(RD)的屈服强度最高(104.3 Mpa)，而Td的屈服强度最低(68.6Mpa)，这意味着屈服强度对织构的依赖程度很高。在RD、45°和TD试样中观察到了变形机制的转变，即基滑移(epsilon=0.5%)-GT；基滑移+非基滑移(epsilon=1.5%)->；基滑移+非基滑移+孪生(epsilon=7.5%)，非基滑移被激活以适应变形过程中基滑移所施加的剪应力的增加。此外，变形模式的各向异性也很明显。在epsilon=0.5%时，TD样品的底部滑移主要发生在高施密德因子(SF>；=0.35)的颗粒中，而在RD样品中，底部滑移的SFS分布较广，也存在棱柱状滑移。当应变达到7.5%时，孪生在TD试件中的作用比45度和RD试件更大。此外，织构对加工硬化行为有很大的影响。当ε=1.5%时，加工硬化率由基面滑移的SF分布决定。颗粒越多，基面滑移的SF越低，WH率越高。然而，孪生在Ep=7.5%时对加工硬化率有重要影响，因此孪晶面积分数(f(孪晶))最大的TD样品的加工硬化率最高。(C)2019爱思唯尔B.V.保留所有权利。
The influence of crystallographic texture on deformation mechanism and work-hardening behavior of the Mg-2Zn-0.1Ca alloy sheet was investigated via quasi-in-situ slip traces analysis. The results show that the sheet displayed a weakened transverse direction (TD) spread texture. The rolling direction (RD) sample exhibited the highest yield strength (104.3 MPa), while the TD samples exhibit the lowest (68.6 MPa), implying a high dependency of yield strength on texture. A deformation mechanism transition were observed in the RD, 45 degrees and TD samples, i.e. basal slip (epsilon = 0.5%) -> basal slip + non-basal slip (epsilon = 1.5%) -> basal slip + non-basal slip + twinning (epsilon = 7.5%), and non-basal slip was activated to accommodate the imposed deformation due to the increment in an applied shear stress for basal slip with deformation processing. Additionally, the anisotropy of deformation modes is pronounced. At epsilon = 0.5%, basal slip primarily operated in the grains with high Schmid Factor (SF >= 0.35) in TD sample, while in the RD sample, the SFs for basal slip exhibited a wider distribution and prismatic slip also operated. As strain reached to 7.5%, twinning played more important role in the TD sample than the 45 degrees and RD samples. Moreover, the texture has a substantial influence on work hardening behavior. At epsilon = 1.5%, work hardening rate was governed by SF distribution for basal slip. The sample with more grains exhibiting low SF for basal slip shows higher WH rate. However, twinning plays an important role in effecting work hardening rate at epsilon = 7.5%, and consequently the TD sample with the greatest area fraction of twin (f(twin)) has the highest work hardening rate. (C) 2019 Elsevier B.V. All rights reserved.