Zhang Y, Hackett BL, Dong J, Xie KY, Pharr GM. Evolution of dislocation substructures in metals via high-strain-rate nanoindentation.
Proc Natl Acad Sci U S A 2023;
120:e2310500120. [PMID:
38060557 PMCID:
PMC10723145 DOI:
10.1073/pnas.2310500120]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/27/2023] [Indexed: 12/17/2023] Open
Abstract
Deformation at high strain rates often results in high stresses on many engineering materials, potentially leading to catastrophic failure without proper design. High-strain-rate mechanical testing is thus needed to improve the design of future structural materials for a wide range of applications. Although several high-strain-rate mechanical testing techniques have been developed to provide a fundamental understanding of material responses and microstructural evolution under high-strain-rate deformation conditions, these tests are often very time consuming and costly. In this work, we utilize a high-strain-rate nanoindentation testing technique and system in combination with transmission electron microscopy to reveal the deformation mechanisms and dislocation substructures that evolve in pure metals from low (10-2 s-1) to very high indentation strain rates (104 s-1), using face-centered cubic aluminum and body-centered cubic molybdenum as model materials. The results help to establish the conditions under which micro- and macro-scale tests can be compared with validity and also provide a promising pathway that could lead to accelerated high-strain-rate testing at substantially reduced costs.
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