Abstract

The present study investigates the grain refinement of Mg–3Al, Mg–6Al and Mg–9Al alloys by calcium addition. The maximum reduction in grain size has been observed at 0.2% Ca addition in Mg–Al alloys, in which any further addition (up to 0.4%) has marginal improvement in grain refinement. The mechanism associated with the grain refinement of Mg–Al alloys by Ca addition is discussed in terms of growth restriction factor (Q) and constitutional undercooling (ΔTCS) using analytical model. The influence of growth restriction factor (Q) on the final grain size of Ca-added Mg–Al alloys are calculated with the help analytical model by assuming that the number of nucleant particles is not altered through Ca addition. For accurate grain size calculations, the value of Q has been estimated with reliable thermodynamic database using Scheil solidification simulation. The comparison of predicted and experimental grain size results indicate that constitutional undercooling activation of nucleation events plays dominant role in grain refinement in Mg–Al alloys by calcium addition, whereas the increase in growth restriction value has negligible effect.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.