The Influence of Rare Earth, Strontium and Calcium on the Thermal Diffusivity of Mg-Al Alloys
| Periodical | Defect and Diffusion Forum (Volumes 312 - 315) |
|---|---|
| Main Theme | Diffusion in Solids and Liquids VI |
| Edited by | Andreas Öchsner, Graeme E. Murch and João M.P.Q. Delgado |
| Pages | 824-829 |
| DOI | 10.4028/www.scientific.net/DDF.312-315.824 |
| Citation | Tomasz Rzychoń et al., 2011, Defect and Diffusion Forum, 312-315, 824 |
| Online since | April, 2011 |
| Authors | Tomasz Rzychoń, Andrzej Kiełbus |
| Keywords | Magnesium Alloy, Thermal Diffusivity |
| Price | US$ 28,- |
The microstructure and thermal diffusivity of as-cast AM60, AE63, AJ63 and AXJ620 alloys were investigated over the temperature range 20–300°C. The microstructure of as-cast AM60 magnesium alloy consists of dendrites of α-Mg solid solution and divorced eutectic containing “islands” of α-Mg and Mg17Al12 phase. In regions adjacent with divorced eutectic, the supersaturation aluminum solute in the α-Mg matrix is observed. The addition of rare earth, calcium and strontium caused the decrease of the volume fraction of Mg17Al12 compound and aluminum content in α-Mg solid solution. Moreover, the intermetallic compounds such as: Al11RE3, Al4Sr, Al3Mg13Sr, Al2Ca are observed in the interdendritic regions. The thermal diffusivity of AM60 magnesium alloy increases with increasing temperature up to 150°C, above this temperature the increase is less marked. The change in the slope of the temperature variation of the thermal diffusivity is caused by a precipitation of Mg17Al12 phase in the supersaturation of α-Mg areas neighboring the divorced eutectic α-Mg+Mg17Al12. The addition of rare earth, calcium and strontium caused the increase of the thermal diffusivity and thermal conductivity due to the decreasing of aluminum content in α-Mg matrix.
