Abstract
Eutectic high-entropy alloys(EHEAs),as a classification of high-entropy alloys(HEAs),have received worldwide interest due to superior fluidity and attractive properties.However,other than the FCC+B2 EHEA system,most other reported EHEA systems show inherent brittleness during tensile loading at room temperature,which limits their advanced engineering application.In this work,a novel spheroidization+recrystallization(SR)strategy for synergistic strengthening and plasticizing of the brit-tle CoCrFeNi2(V6B3Si)o.149 was proposed.The superior combination of strength and ductility was achieved by tailoring spherical M3B2+recrystallized FCC duplex phases.Based on this strategy,the yield strength and elongation were improved from 565±15 MPa and 2.3％±03％to 841±24-1278±20 MPa and 14.7％±0.5％-22.5％±1.2％,with an increase of 48％-126％and 539％-878％,respectively.The synergistic increment in the strength and ductility of SR-FCC+M3B2 EHEAs exceeds all reported fur-ther strengthened FCC+B2 EHEAs.Meanwhile,such simple thermo-mechanical processing is suitable for large-scale industrial production.The high strength results from the back stress provided by the dual heterogeneity of FCC grain sizes and soft FCC/hard M3B2.The good ductility is attributed to the dislo-cation movement path released by spheroidized M3B2 and a more uniform stress distribution caused by the recrystallized FCC.This work provides a new strategy for synergistic strengthening and plasticizing of the brittle EHEAs to meet industrial reliability requirements.
基金项目
National Key Research and Development Program of China(2018YFA0702901)
National Natural Science Foundation of China(U20A20278)
Liao Ning Revitalization Talents Program(XLYC1807047)
NETL
NSTL
万方数据