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.

Modifying the Microstructure and Mechanical Properties of Non-Heat Treated HPDC AlSi10MnMg Foundry Alloy via Incorporation of TiB₂ Particles and Sc

“…Heterogeneous nucleation has a stronger refining effect and can significantly refine the α-Al grains to enhance the mechanical properties. Iron is inevitably taken up in the HPDC process and is also a beneficial minor alloying element in the aluminum alloys for ejection and die-release [46]. However, owing to its poor equilibrium solubility in the α-Al solid solution phase, excessive Fe is considerably deleterious to ductility.…”