Effects Of Cu And Rare Earth Element On The Microstruture And Properties Of Mg-7Zn-6Al Magnesium Alloy

Cast magnesium alloys have been widely used in the industrial fields because of its fine casting properties,as well as the corrosion resistance ability,especially the Mg-Al-Zn magnesium alloys. Though there are some problems in the Mg-Zn-Al magnesium alloys in terms of its casting properties and mechanical properties under room and elevated temperatures which can't be gaind at the same time. Alloying and refinement of the magnesium alloys are the two main ways to improve the comprensive properties of the alloys. How to improve the comprehensive properties of the Mg-Zn-Al magnesium alloys and extend its application while maintaining its fine casting properties still remain a problem.Mg-7Zn-6Al magnesium alloys are the main subjects studied in this paper, the trends of changing in the microstructure and mechanical properties of the alloys under as-cast by adding Cu and rare earth elements are studied. Results show that:eutectic phases are modified, which can improve the eutectic temperature. The trends of tensile strength of the magnesium alloys under as-cast conditions are different from the increment of Cu element.Al2Y(AlNd) phase appears by adding Nd or Y into Mg-7Zn-6Al-xCu magnesium alloys. Tensile strength and elongation reaches 174MPa and 8.00% seperately with 0.9% Nd and 0.9% Cu together, which has a better mechanical properties compared with the matrix magnesium alloys.