In 6061 aluminum alloy is AL - Mg - Si system with moderate heat treatment strengthening alloy, Mg and Si are the main alloy elements, optimizing chemical composition of the main work is to determine the percentage content of Mg and Si (mass fraction, the same below).1.1 Mg of the role and influence of Mg and Si strengthening phase Mg2Si, the higher the content of Mg, the more the amount of Mg2Si, heat treatment reinforcement effect is more big, the profile of the tensile strength is high, but also increase deformation resistance, alloy plastic drop, processing performance is bad, the corrosion resistance worse.1.2 the number of function and influence of Si Si should make all Mg in the alloy can exist in the form of Mg2Si phase, in order to ensure that the Mg at full play. As Si content increasing, the grain size of alloy and metal liquidity increases, casting performance is good, heat treatment reinforcement effect increased, the tensile strength of profiles plasticity is reduced, and the corrosion resistance worse.
