Optimizing Zr addition method to improve the comprehensive high temperature performance of Al-Fe-Ni-Sc eutectic alloy

This work studies the addition method of Zr to the Al-Fe-Ni-Sc eutectic alloys. The Sc/Zr ratio and the total atomic content of Sc and Zr have been changed to explore the influence of Zr addition to the eutectic alloy. The microstructure variation exhibits that Zr addition can introduce inevitable grain refinement, which increases with the Zr addition or the total atomic content. The hardness variation during thermal exposure reveals that the stability of alloy depends on the Sc/Zr ratio. The fundamental relationship between thermal stability of precipitate and its structure or composition has been discussed by both thermodynamic and morphological factors. Comparably, the comprehensive high temperature performance is deemed to be deteriorated by the intensive grain refinement. Thus, a suitable Zr addition should be achieved to balance the improvement of thermal stability and weaken of high temperature tensile property. Above all, it is suggested that replacing Sc with proper Zr content to control the total atomic content and Sc/Zr ratio is an appropriate route to improve comprehensive high mechanical property of the Al-Fe-Ni-Sc eutectic alloy. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates that the addition of Zr to Al-Fe-Ni-Sc eutectic alloys can refine the grain structure, improve thermal stability, but a balance between thermal stability and high temperature tensile properties needs to be achieved. Appropriate Zr content can enhance the comprehensive high temperature performance of the eutectic alloy.