Thermomagnetic Processing of Aluminum Alloys During Heat Treatment

David Weiss,Michael S. Kesler,Hunter B. Henderson,Aurelien Perron,Michael J. Thompson,Bart Murphy,Gerard M. Ludtka,Orlando Rios

doi:10.1007/s40962-020-00460-z

Abstract

Processing materials under magnetic fields is an underexplored technique to improve structure and mechanical properties in metals and alloys. Magnetic fields can alter phase stability, modify diffusion characteristics, and alter material flow substantially. In castings, magnetic fields can be used during melting of the alloy, during solidification, or during postprocessing operations such as heat treatment to achieve structural changes. This work investigates the effectiveness of thermomagnetic processing during heat treatment of Al alloys containing in the Al–Cu, Al–Si–Cu, and Al–Mg–Ce systems. We demonstrate an improvement in mechanical properties and a reduction in required heat treatment times for all alloys.

Highlights

Work in ferrous materials has demonstrated that high magnetic field processing (HMFP) can induce meaningful changes in kinetics, phase equilibria, and solubility limits in the solid state.[1,2,3] These processing routes can result in modified microstructures that, for example, retain alloying elements in solution
All HMFP solution heat-treating and aging times employed in this study were significantly shorter than the conventionally required times
Microstructural analyses suggest that the high magnetic fields enable faster dissolution of solute during the solution heat-treating cycle, resulting in finer and more copious strengthening precipitates after the aging cycle

Summary

Introduction

Work in ferrous materials has demonstrated that high magnetic field processing (HMFP) can induce meaningful changes in kinetics, phase equilibria, and solubility limits in the solid state.[1,2,3] These processing routes can result in modified microstructures that, for example, retain alloying elements in solution. This potentially negates the need for a solution heat treatments and/or increase maximum solid solubility limits, improving the strength of the alloy. Though the strongest thermodynamic effects are found in materials with in ferro- or ferrimagnetic phases below their This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/ downloads/doe-public-access-plan)

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Conclusion