Effect Of Microalloying Of Zr And Er On Microstructure And Properties Of 6061 Aluminum Alloy

In the environment of energy saving and environmental protection,reducing vehicle weight to reduce energy consumption,reducing emissions and improving efficiency,have become an important direction for the automobile enterprises to improve the competitiveness.The demand for automobile lightweight is increasingly enhanced,so the aluminum alloy plate used in automobile body is one of the hotspots of research and application at present.The 6 series alloy not only has good thermoplastic,excellent corrosion resistance and ideal comprehensive mechanical properties but also easy to oxidize and coloring,so it is an ideal material for automotive body aluminum alloy sheet.However,the formability of the aluminum plate is worse than that of the steel plate,thus limiting its large-scale application on the car.Therefore,in view of the problems,the 6061 alloy was taken as the research object in this paper,and the micro-alloying effect of alloying element and the heat treatment process were investigated.The research contents can be concluded as follows:6061 aluminum alloy ingots containing different alloying elements(Zr and Er)were prepared by ingot metallurgy method.Homogenization treatment,rolling deformation,solid solution treatment,natural aging treatment and artificial aging treatment were carried out for the alloy ingot.The effects of Zr and Er elements on Microstructure and properties of 6061 aluminium alloy casting ware studied.The addition of alloy elements is optimized,and the homogenization process of alloy is explored.The effects of Zr and Er elements on forming properties of 6061 alloy sheet ware studied and and the drawing process of 6061 alloy was simulated by finite element numerical simulation.The optimum solution and aging system of alloy sheet and the effects of Zr and Er elements on the microstructure and properties of T6 6061 alloy sheet ware studied.The results show that adding 0.2%Zr alone,adding 0.3%Er alone and adding 0.3%Er and 0.15%Zr together can improve the casting structure of 6061 alloy effectively.Zr,Er elements can reduce dendrite spacing,refine grain and improve the mechanical properties of 6601 alloy.After rolling and homogenization treatment,the forming property of 6061-0.3Er-0.15 Zr alloy is the best,for its strength is the highest,the n value and r value is the largest,the elongation is 25%,and the limit drawing coefficient is 0.52.The 6061-0.3Er alloy is the next,while the 6061-0.2Zr alloy has poor formability.Under T6 condition,6061-0.3Er-0.15 Zr alloy has uniform microstructure and fine grain size,and its average grain size is 45?m,which has the most obvious improvement in mechanical properties and its tensile strength,yield strength and elongation are 353 MPa,275 MPa and 25.7% respectively.