|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Magnesium Alloy Development: An LMD Symposium in Honor of Karl Kainer
||Thermodynamics of Phase Formation in Mg–Al–C Alloys Applied to Grain Refinement
||Guillaume Deffrennes, Bruno Gardiola, Marc Lomello, Jérôme Andrieux, Olivier Dezellus, Rainer Schmid-Fetzer
|On-Site Speaker (Planned)
Grain refinement of Mg-Al based alloys is challenging because it is known that Zr, which is extremely effective in many Al-free alloys, cannot be used. The addition of carbon through various routes by using carbon-containing sources is considered as an option. The grain refinement mechanisms are still under debate. The present work is focused on the ternary base system Mg-Al-C, including the potential nucleants Al4C3 and Al2MgC2, presently without consideration of Al2CO. Phase formation in the Mg-Al-C system will be discussed and a tentative ternary phase diagram is presented. It is based on a Mg-Al-C thermodynamic description providing the thermodynamic stabilities of Al4C3 and Al2MgC2 and driving forces for their formation in the ternary system. This description is validated by ternary key experiments and also includes the experimentally validated Mg-C phase diagram. Quantitative calculation of the segregation effect and growth restriction factor are also provided.