The breakdown of strength size scaling in spherical nanoindentation and microcompression of metallic glasses

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• 作者：S. Wang^a ; ^{songwang4@cityu.edu.hk} ; Y.F. Ye^a ; Q. Wang^b ; S.Q. Shi^c ; Y. Yang^a ; ^{yonyang@cityu.edu.hk}
• 关键词：Metallic glass ; Size scaling ; Shear band initiation
• 刊名：Scripta Materialia
• 出版年：2017
• 出版时间：15 March 2017
• 年：2017
• 卷：130
• 期：Complete
• 页码：283-287
• 全文大小：877 K
• 卷排序：130

文摘

It was previously reported that the strength of metallic glasses (MGs) would scale inversely with the size of a sample or a deformation field, commonly known as “smaller-being-stronger”. However, based on the extensive spherical nanoindentation experiments conducted across a variety of MGs, we demonstrate that such strength-size scaling breaks down at a critical indenter tip radius, which is caused by the transition of the yielding mechanism from bulk- to surface-controlled shear band initiation. Our experimental findings also provide an explanation for the unusual strength scattering observed in the micro-compression of MGs.