Abstract
Multilayered steel composites consisting of alternating martensite and austenite layers and exhibiting a combination of high strength and ductility were successfully fabricated. To understand the microplasticity mechanisms responsible for such exceptional mechanical behavior, 3D X-ray microscopy with a submicron beam size was employed to probe the stress/strain distribution within the top two layers during incremental tensile loading. The 3D depth-dependent strain gradients were monitored in situ near the martensite/austenite interfaces as a function of the load level. It was observed that the strain gradients redistributed during loading. Specifically, large compressive strains developed in the top martensite layer transverse to the loading direction, while small tensile strains were found across the layer interface into the underneath austenite layer.
| Original language | English |
|---|---|
| Pages (from-to) | 98-108 |
| Number of pages | 11 |
| Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
| Volume | 45 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2014 |
Funding
This research was sponsored by the U.S. Department of Energy (DOE), Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies as part of the Lightweight Materials Program, and by the DOE Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract DE-AC05-00OR22725 with UT-Battelle, LLC, and performed in part at ORNL’s Shared Research Equipment (SHaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy. The work benefited from the use of the Advanced Photon Source, supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The authors acknowledge Dongxiao Qiao from Oak Ridge National Laboratory and Douglas E. Fielden at the University of Tennessee for their support in the experiments. R.B. was partially supported by U.S. DOE Office of Science Basic Energy Sciences. The authors wish to thank Dr. J. Vitek (ORNL) for reviewing the manuscript.