Mechanism of the Mg<sub>3</sub>Bi<sub>2</sub> Phase Formation in Pb-Free Aluminum 6xxx Alloy with Bismuth Addition

In the present work, free-cutting aluminum alloy AA6026 with 1.1 wt.% bismuth addition was fabricated by different melt preparation methods in order to investigate whether the melt preparation route affects the solidification sequence and thus has an influence on the machinability of the alloy. All...

Full description

Bibliographic Details
Main Authors: Simon Rečnik, Milan Bizjak, Jožef Medved, Peter Cvahte, Blaž Karpe, Aleš Nagode
Format: Article
Language:English
Published: MDPI AG 2021-04-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/11/4/424
Description
Summary:In the present work, free-cutting aluminum alloy AA6026 with 1.1 wt.% bismuth addition was fabricated by different melt preparation methods in order to investigate whether the melt preparation route affects the solidification sequence and thus has an influence on the machinability of the alloy. All experiments were designed to simulate variable industrial conditions: addition of bismuth in an induction melting furnace, addition of bismuth in an electric resistance holding furnace, addition of bismuth together with grain refiner, effect of holding time and melt temperature before casting. Detailed thermodynamic analyses (DSC, Thermo-Calc) and microstructural characterization (SEM-EDS, XRD) have been performed to explain the solidification sequence, microstructure development and especially formation of the intermetallic Mg<sub>3</sub>Bi<sub>2</sub> phase.
ISSN:2073-4352