Effects of Sc on the microstructure and properties of in situ ZrB₂/7085Al composites

Abstract

The microstructure and mechanical properties of the ZrB₂/7085Al composites containing Sc were studied. The ZrB₂/7085Al composites were prepared by in situ reaction via Al-Zr-B system. On addition of Sc, it interacted with Zr present in the alloy resulting in the production of Al₃(Sc, Zr) precipitates. Minor addition of Sc resulted in grain refinement, change in ZrB₂ nanoparticles distribution, change in the size and morphology of the η phase and formation of Al₃Sc and Al₃(Sc, Zr) precipitates, which improved the strength significantly. The ultimate tensile strength (UTS), yield strength (YS) and elongation of 7085Al-ZrB₂-Sc increased to 660.2, 603.4 MPa and 10.6%, respectively. These tensile properties improved 20.4%, 19.2% and 73.7%, respectively, over the 7085Al.

KEYWORDS:

• ZrB₂ nanoparticles
• Al₃Sc
• Al₃ (Sc
• Zr)
• strengthening mechanism
• GPA

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was financially sponsored by the National Natural Science Foundation of China (Nos. U20A20274, U1664254, 52071158, 51701085), the Six Talents Peak Project of Jiangsu Province (2018-XCL-202), the Open Funds of SKLMMC of SJTU (MMC-KF18-16), the Jiangsu Province Key Laboratory of High-end Structural Materials (HSM1803, 1902).