Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971640 | Materials Science and Engineering: A | 2018 | 17 Pages |
Abstract
To achieve balance of high strength and high ductility remains a difficult problem for metallic materials, especially in as-cast alloys. We combined the design concepts of high-entropy alloys (HEAs) and Ni-based superalloys, and designed two new Ni48.7Co17.5Cr10Fe9.3Al7.5Ti7 and Ni47.7Co17.5Cr10Fe9.3Al7.5Ti7Mo1 (at%) precipitation-hardened cast HEAs. Both two alloys have face-centered cubic (fcc) high-entropy matrix + nano γⲠ(Ni3(Al,Ti)-type) particles structure. Fine γⲠparticles with the average diameter less than 70â¯nm and 130â¯nm are homogeneously distributed in dendritic regions and inter-dendritic regions, respectively. The yield strength of Ni47.7Co17.5Cr10Fe9.3Al7.5Ti7Mo1 alloy is 899â¯MPa, ultimate tensile strength is 1064â¯MPa and elongation is 14.3%. The strengthening theory is discussed. Attributable to substantial γⲠprecipitates, shearing strengthening mechanism plays an important role. Fracture is caused by micron-sized eutectic γⲠphases that lead to stress concentration.
Related Topics
Physical Sciences and Engineering
Materials Science
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Authors
Lu Zhang, Yang Zhou, Xi Jin, Xingyu Du, Bangsheng Li,