Metallographic preparation methods for the Mg based system Mg-Al-Ca and its Laves phases

Abstract

The Mg-Al-Ca system has been shown to be a promising alloy system since it combines the low density of Mg with a high creep resistance at high alloying contents and a high ductility for dilute alloys, while simultaneously avoiding the requirement of alloying with costly rare earth elements. Nevertheless, the adequate preparation of the alloy system for subsequent microstructural, mechanical, electrochemical and defect analysis is challenging. Therefore, within this publication, we present and apply methods for the structural, mechanical, electrochemical and defect analysis with a focus on the corresponding required metallographic preparation methods in order to support research on the alloy system. • For solid solution Mg-Al-Ca and Mg-Al-Ca composites, electropolishing is required for EBSD, slip trace analysis and micromechanical tests • No electropolishing was applied to avoid chemical modification of the specimen surface if corrosion testing was performed • The CaMg 2 Laves phase required electropolishing for subsequent EBSD analysis and micromechanical testing, but would result in an undesired topography for the CaAl 2 phase