Strength, plasticity and brittleness of bulk metallic glasses under compression: statistical and geometric effects
Strength, plasticity and brittleness of bulk metallic glasses under compression: statistical and geometric effects
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DOI：
10.1080/14786430701762619
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发表时间：
2008-01-01
影响因子：
1.6
通讯作者：
Schuh, C. A.
中科院分区：
文献类型：
--
作者：
Wu, W. F.;Li, Y.;Schuh, C. A.
为了研究块体金属玻璃（BMG）的缺陷敏感性和可靠性，对大量具有统计学意义的试样进行了压缩试验。尽管BMG在失效前表现出很小或没有宏观塑性（类似于其他脆性材料），但我们观察到令人惊讶的高抗压强度均匀性。威布尔分析研究强度的统计分散，得到非常高的威布尔模量约25的本质上脆性玻璃，和接近75的本质上可延展的。这种高均匀性对于在结构应用中使用BMG是令人鼓舞的。此外，我们说明，微妙的缺陷，在测试几何形状（即误切或偏离正交性）显着影响压缩响应。在脆性玻璃中，这些作为失效临界缺陷，而在韧性玻璃中，它们限制剪切带，导致测试过程中的倾斜和弯曲，并引起误导性的宏观测量塑性变形。
To investigate the flaw sensitivity and reliability of bulk metallic glasses (BMGs), compressive testing was performed on a statistically significant number of specimens. Despite the fact that BMGs exhibit little or no macroscopic plasticity before failure (similar to other brittle materials), we observe surprisingly high uniformity in compressive strength. Weibull analysis was employed to study the statistical dispersion in strength, giving very high Weibull moduli of about 25 for an intrinsically brittle glass, and near 75 for an intrinsically malleable one. This high uniformity is encouraging for the use of BMGs in structural applications. Furthermore, we illustrate that subtle imperfections in the test geometry (i.e. miscut or deviations from orthogonality) dramatically affect the compression response. In brittle glasses these act as failure-critical flaws, whereas in malleable glasses they constrain shear bands, lead to tilting and bending during testing, and give rise to misleading macroscopic measurements of plastic deformation.