Effects of Zn and Mg Amounts on the Properties of High Thermal Conductivity Al-Zn-Mg-Fe Alloys for Die Casting

The effects of Zn and Mg amounts on the solidification characteristics, microstructure, thermal conductivity and tensile strength of Al-Zn-Mg-Fe alloys were investigated for the development of high thermal conductivity aluminium alloys for die casting. Zn and Mg amounts in Al-Zn-Mg-Fe alloys had a little effect on the liquidus / solidus temperature, the latent heat for solidification and the fluidity of Al-Zn-Mg-Fe alloys. Thermo-physical modelling of Al-Zn-Mg-Fe alloys by JMatPro program showed MgZn2, AlCuMgZn and Al3Fe phases on microstructure of their alloys. Increase of Zn and Mg amounts in Al-Zn-Mg-Fe alloys resulted in gradual reduction of the thermal conductivity of their alloys. Increase of Mg amounts in Al-2%Zn-Mg-Fe alloys had little effect on the ten-sile strength of their alloys, but increase of Mg amounts in Al-4%Zn-Mg-Fe alloys resulted in steep increase of the tensile strengt