Role Of Scandium In Crack Mitigation And Grain Refinement Of Additively Manufactured Al6061 Alloy

Authors:

Faezeh Hosseini (University of Alberta, Canada)
Allison Thome (University of Alberta, Canada)
Asad Asad (University of Alberta, Canada)
Arthur Mar (University of Alberta, Canada)
Mostafa Yakout (University of Alberta, Canada)

Abstract:

Processing high-performance aluminum (Al) alloys via laser additive manufacturing (AM) faces challenges, primarily due to rapid cooling rates that often lead to hot cracking. In this work, we explore a strategy of modifying the composition of Al6061 by doping Scandium (Sc) to reduce susceptibility to cracks and control the microstructure with crack-free, near-equiaxed grains using the laser powder bed fusion (L-PBF) technique. The optimal quantity of Sc doped in Al6061 for grain refinement was determined using induction melting with doping levels of 0.1–0.5 wt% Sc. Sc-doped Al6061 powder was prepared for L-PBF using mechanical alloying via optimized ball milling parameters to ensure uniform distribution of Sc within the alloy system. The microstructural evolution of the Sc-doped Al6061 alloy was studied in relation to L-PBF process parameters. Under the optimized Sc content and optimal laser power and scanning speed, near-equiaxed grains were formed along the building direction, with no defects.

DOI:

https://doi.org/10.59499/EP256779578