Abstract
Dynamic (up to 5500 s−1) and quasi-static compression tests are conducted on a 15 wt% B4C particle-reinforced Al (B4C/Al) composite. In situ, high-speed synchrotron X-ray phase contrast imaging and digital image correlation are employed to map mesoscale deformation fields at μm and μs scales. The bulk stress–strain curves show significant strain and strain-rate hardening under dynamic compression. The strain-rate sensitivity exponent is an order of magnitude higher at high strain rates (>103 s−1) than that at low strain rates (<10−2 s−1). Strain field mapping demonstrates distinct compressive strain localizations for both quasi-static and dynamic loading. Nevertheless, compressive strain localizations appear denser in spacing under dynamic loading, owing to spontaneous dislocation nucleation in both weak and strong zones. This results in a higher density of geometrically necessary dislocations, which contributes to the higher strain and strain-rate hardening of B4C/Al under dynamic loading. The ratio of the maximum local strain to the bulk average is ~1.5, and the local strain-rate enhancement cannot explain the increased rate sensitivity of B4C/Al under dynamic loading. Therefore, the rate-dependent deformation heterogeneity dominates the strain-rate hardening of B4C/Al. Postmortem analyses help correlate deformation features to particle- and grain-scale microstructures, yielding consistent results with mesoscale strain fields.
Original language | English (US) |
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Pages (from-to) | 16141-16151 |
Number of pages | 11 |
Journal | Ceramics International |
Volume | 47 |
Issue number | 11 |
DOIs | |
State | Published - Jun 1 2021 |
Funding
This work was sponsored in part by the National Natural Science Foundation of China (Grant Nos. 11802252 and 11627901) and the Science and Technology Program of Sichuan Province (Grant No. 2020YFG0415). Use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the US DOE under Contract No. DE-AC02-06CH11357.
Keywords
- BC/Al composite
- Deformation heterogeneity
- Strain-rate effect
- X-ray digital image correlation
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry