Yield strength and yield strain of metallic glasses and their correlations with glass transition temperature
Yield strength and yield strain of metallic glasses and their correlations with glass transition temperature
复制标题
DOI：
10.1016/j.jallcom.2015.03.005
复制
发表时间：
2015-07
影响因子：
6.2
通讯作者：
R. Qu;Liu Zisen;R. Wang;Z. Zhang
中科院分区：
文献类型：
--
作者：
R. Qu;Liu Zisen;R. Wang;Z. Zhang
强度是金属玻璃最突出的力学性能。在这里，我们分析了镁合金的强度与超过300个组成的合金系统，涵盖几乎所有的强度水平，从0.3 GPa到6 GPa。有了这些丰富的实验数据，我们发现，屈服应变并不总是恒定的，但取决于玻璃化转变温度，Tg，范围从1%至2.5%的正常应变和从1.2%至3.4%的剪切应变。这可以通过假设屈服和玻璃化转变的等效能垒来很好地解释。基于这一假设导出的关系式表明，高Tg的镁合金可以在较大的临界应变和较高的强度下屈服，这意味着镁合金可以同时实现高弹性、高强度和高热稳定性。
Strength should be the most outstanding mechanical property for metallic glasses (MGs). Here we analyze the strengths of MGs with more than 300 compositions in ∼30 alloy systems covering nearly all strength levels, ranging from 0.3 GPa to 6 GPa. With these abundant experimental data available, we find that the yield strain is not always constant but depends on glass transition temperature,Tg, ranging from 1% to 2.5% for normal strain and from 1.2% to 3.4% for shear strain. This can be well explained by assuming an equivalent energy barrier for yielding and glass transition. Relations derived based on this assumption show that MGs with highTgmay yield with larger critical strain and higher strength, implying that high elasticity, high strength and high thermostability can be synchronously achieved for MGs.