We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Effect of Zr micro-alloying on microstructure refinement and mechanical property of CoCrNi medium-entropy alloy processed by high-pressure torsion and subsequent annealing.
- Authors
Rathod, Bhukya Devendar Singh; Gholizadeh, Reza; Park, Myeong-heom; Yoshida, Shuhei; Tsuji, Nobuhiro
- Abstract
Medium-entropy alloys (MEAs) have recently emerged as potential replacements for traditional alloys in high-performance applications. Among the various MEAs developed, equi-atomic CoCrNi MEA stands out for its excellent mechanical performance. Nevertheless, the yield strength of this MEA having a single-phase FCC structure is not exceptionally high. This study suggests a novel approach to strengthen the MEA by adding a small quantity of Zirconium (0.2 at.%). A (CoCrNi)99.8Zr0.2 MEA was cast and homogenized, alongside a CoCrNi MEA for comparison purposes. The alloys underwent high-pressure torsion followed by annealing in a temperature range of 700–1100 °C. In the Zr-doped MEA, annealing resulted in the recrystallization within the FCC matrix, accompanied by the precipitation of finely dispersed particles (Ni7Zr2). The concurrent precipitation hindered the grain growth, maintaining refined grain sizes (0.17 – 4 µm) over a wide range of temperatures. In contrast, the grain size in the Zr-free counterpart increased rapidly above 10 µm at elevated temperatures. The Zr doping substantially increased the yield strength with a minor negative impact on the ductility. The strength enhancement was due to grain refinement, precipitation, and dislocation locking caused by the Zr segregation at dislocation sites. These phenomena and their impacts on the Hall–Petch relationship were investigated and discussed. This study proves micro-alloying as a promising strategy for strengthening MEAs, making these alloys superior to their traditional counterparts.
- Subjects
MICROALLOYING; FACE centered cubic structure; MICROSTRUCTURE; GRAIN refinement; RECRYSTALLIZATION (Metallurgy)
- Publication
Journal of Materials Science, 2024, Vol 59, Issue 14, p5736
- ISSN
0022-2461
- Publication type
Article
- DOI
10.1007/s10853-023-09244-2