par Jiang, L.;Godet, Stéphane ;Jonas, J.J.;Huang, G.;Luo, Alan
Référence International Symposium on Light Metals and Metal Matrix Composites(22.08.2004-25.08.2004: Hamilton, ON, Canada), Light Metals and Metal Matrix Composites, page (477-490)
Publication Publié, 2004
Publication dans des actes
Résumé : This report investigated the dynamic recrystn. (DRX) phenomenon in Mg alloy AZ31 billets to understand the deformation mechanisms and microstructure evolution during extrusion and other metal forming processes. Compression tests of coarse-grained as-cast Mg alloy billets contg. lamellar Mg17Al12 eutectic phase and (Al, Mn) particles suggest that temps. higher than 300°, strains greater than 0.25 and strain rates above 0.1/s lead to the formation of fine DRX grains in the deformed samples. Microstructural observations also indicate particle-stimulated DRX nucleation (PSN) during hot deformation of the AZ31 alloy, facilitated by the presence of Mg17Al12 and (Al, Mn) particles. While the Mg17Al12 is dissolved into the matrix at about 350°, (Al, Mn) particles may remain effective for PSN at temps. up to at least 400°C. Alloy design with a proper distribution of second-phase particles can provide the desired microstructure for improved properties and formability in wrought Mg alloys.