Journal
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
Volume 49A, Issue 5, Pages 1931-1947Publisher
SPRINGER
DOI: 10.1007/s11661-018-4507-5
Keywords
-
Funding
- National Key Research and Development Program of China [2016YFB0301102]
- JSPS [16K18266]
- National Nature Science Foundation of China [51571068]
- JST Advanced Low Carbon Technology Research and Development Program (ALCA) [12102886]
- Grants-in-Aid for Scientific Research [16K18266] Funding Source: KAKEN
Ask authors/readers for more resources
An ultra-strong and ductile Mg-8.2Gd-3.8Y-1Zn-0.4Zr (wt pct) alloy was developed by using hot extrusion to modify the microstructure via forced-air cooling and an artificial aging treatment. A superior strength-ductility balance was obtained that had a tensile yield strength of 466 MPa and an elongation to failure of 14.5 pct. The local strain evolution during the in situ testing of the ultra-strong and ductile alloy was quantitatively analyzed with high-resolution electron backscattered diffraction and digital image correlation. The fracture behavior during the tensile test was characterized by synchrotron X-ray tomography along with SEM and STEM observations. The alloy showed a bimodal microstructure, consisting of dynamically recrystallized (DRXed) grains with random orientations and elongated hot-worked grains with parallel to the extrusion direction. The DRXed grains were deformed by the basal aOE (c) a > slip and the hot-worked grains were deformed by the prismatic aOE (c) a > slip dominantly. The strain evolution analysis indicated that the multilayered structure relaxed the strain localization via strain transfer from the DRXed to the hot-worked regions, which led to the high ductility of the alloy. Precipitation of the gamma' on basal planes and the beta' phases on the prismatic planes of the alpha-Mg generated closed volumes, which enhanced the strength by pinning dislocations effectively, and contributed to the high ductility by impeding the propagation of micro-cracks inside the grains. The deformation incompatibility between the hot-worked grains and the arched block-shaped long-period stacking ordered (LPSO) phases induced the crack initiation and propagation, which fractured the alloy.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available