Investigation on the Controllable Microstructures of High Iron Content Al–Fe Alloys Fabricated via Solid–Liquid Mixture Method Combining with Plasma Arc Heating Approach

Abstract

Al-Fe alloys, with large amounts of sphere-like structures, few plate-like structures, and little needle-like structures of micron scale second phase have been successfully prepared via a new type of solid-liquid mixture approach combined with plasma arc heating (PAH). The authors have obtained Al-Fe alloys with iron content of 0-15%, which is of extremely significance that thermal plasma jet (TPJ) breaks through the limitation of low iron content in Al-Fe alloys. Microstructures characterization indicates that not only the microstructures of Al-Fe alloys are refined, but also the morphologies are optimized. Meanwhile, sharp corners of iron powders are rounded off and impurities are removed under the action of PAH, which is important for improving mechanical property of Al-Fe alloys. And then, the effects of various parameters including PAH, iron content, and melt temperature on the microstructures and mechanical performance are systematically investigated. The possible influence mechanisms of parameters are investigated and put forward, and appropriate parameters have been obtained during the processing of Al-Fe alloys via TPJ.