Synergistic refining mechanism of Mg-3％Al alloy refining by carbon inoculation combining with Ca addition

作者：Chengbo Li; Shuqing Yang; Jun Du; HengBin Liao; Gan Luo

来源：镁合金学报（英文）, 2020, 8(4): 1090-1101.

• Mg-Al alloys
• Grain refinement
• Carbon inoculation
• Synergistic refinement

Mg-3％Al alloy was refined by carbon inoculation combining with 0.2％Ca addition.High grain refining efficiency was obtained and the synergistic refining mechanism was deeply discussed in the present study.Al-C-O particles,actually A14C3 particles,were formed in the carbon-inoculated Mg-3％Al alloy acting as nuclei for α-Mg grains.Ca addition had no obvious effect on size distribution of the nucleating particles.Ca segregation was proved on Al4C3 particles,which should reduce the interfacial energy of nuclei/Mg.The constitutional undercooling in front of nucleus/liquid was increased from 0.12 ℃ to 0.15 ℃ induced by 0.2％Ca addition.The synergistic grain refining efficiency can be attributed to the higher constitutional undercooling and lower the interface energy of nucleus/Mg induced by Ca addition.More nucleating particles with small size could be activated acting as potent nuclei of α-Mg grains.Consequently,Mg-3％Al alloy could be effectively refined due to the synergistic effect induced by carbon inoculation combining with Ca.

• 单位
  华南理工大学