Study On The Influence Of Rare Earth Modification Of Cast Aluminum Alloy With High Performance

Compared with other series aluminum alloy, Al-Zn-Mg-Cu series alloy has high strength, low density, many advantages and good comprehensive performance, it has good application prospects. Rare earth elements added to the alloy is common, but few reports is about Ce and Er added in the alloy. This paper will use the scanni ng electron microscopy(SEM), universal tensile machine, optical microscope(OM) and other means of adding Ce and combined addition of(Ce, Er) to Al-Zn-Mg-Cu and mechanical properties of as cast microstructure, which to explore the effect of different amount of rare earth additives on alloy. The cast alloy after cold rolling, that aging time in different treatments, influence on the microstructure and mechanical properties of alloy after cold rolling.(1) Rare earth element Ce on the cast microstructure of Al-Zn-Mg-Cu within a certain range of good refining effect of the addition of Ce, the amount of 0.1%, alloy grain began refining and the overall mechanical properties of the alloy to improve;In this experiment, adding 0.2% refinement effect is better, the tensile strength reaches 220 MPa and hardness value reached 72HRB; When added to 0.3%, the grain becomes large and bulky, mechanical properties decrease, but better than the added effect.(2) Ce and Er addition on as cast Al-Zn-Mg-Cu also has very good refining effect, the composite added refinement is better 0.2%, the tensile strength is 10.5% higher tha n that of single addition of rare earth Ce, elongation increased by 7.8% and hardness value increased by 6.4%.(3) Ingot homogenizing treatment for cold rolling, after cold rolling and thermal annealing treatment 450℃/2h. The insulation aging treatment after cold rolling and annealing for different time, when the aging time is 120 /8h, the properties of the alloy is better.Compared with the rare earth elements were added, the mechanical properties are greatly improved.