Evolution of dislocation substructures in metals via high-strain-rate nanoindentation. Academic Article uri icon

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.

published proceedings

  • Proc Natl Acad Sci U S A

author list (cited authors)

  • Zhang, Y., Hackett, B. L., Dong, J., Xie, K. Y., & Pharr, G. M.

complete list of authors

  • Zhang, Yuwei||Hackett, Benjamin L||Dong, Jiaqi||Xie, Kelvin Y||Pharr, George M

publication date

  • December 2023