6063 aluminum alloy is widely used in the construction of aluminum doors and windows and curtain wall frames. In order to ensure that the doors and windows have high wind pressure resistance, assembly performance, corrosion resistance and decorative performance, the comprehensive requirements for aluminum alloy profiles are far higher than those of industry. Profile standards, within the composition range of 6063 aluminum alloy specified in Chinese national standard GB / T3190, different values of chemical composition will result in different profile characteristics. When the range of chemical composition is large, the performance difference will be very large. The range fluctuates, so that the overall performance of the profile cannot be controlled. Therefore, it is preferable that the chemical composition of 6063 aluminum alloy becomes the most important part of producing high-quality aluminum alloy building profiles.
1. The role of alloying elements and its effect on properties 6063 aluminum alloy is a heat-strengthable strengthened alloy with medium strength in the AL-Mg-Si series Aluminium alloy. Mg and Si form the strengthening phase Mg2Si. The higher the content of Mg, the greater the amount of Mg2Si The more the heat treatment strengthens the effect, the higher the tensile strength of the profile, but the deformation resistance also increases, the plasticity of the alloy decreases, and the workability deteriorates.
The role and influence of Si: The amount of Si should be such that all Mg in the alloy can exist in the form of Mg2Si to ensure that the role of Mg is fully exerted. As the Si content increases, the alloy grains become finer, the metal fluidity increases, the casting properties become better, the heat treatment strengthening effect increases, the tensile strength of the profile increases, the plasticity decreases, and the corrosion resistance deteriorates.
2. Selection of Mg and Si content
1. Determination of the amount of Mg2Si: The role of Mg2Si in the alloy is that Mg2Si can be dissolved or precipitated with the change of temperature in the alloy, and exists in the alloy in different forms:
(1) the dispersed mass point dispersed in "B" Is a kind of unstable and will grow up with the increase of temperature.
(2) Excessive "B" is an intermediate metastable substance formed by "B", which will also increase with the temperature. When it grows up, (3) the precipitated substance "B" is a stable substance that grows from the substance B ', which mostly gathers at the grain boundaries and dendrite boundaries, and can play a strengthening role. The amount of Mg2Si is selected. Increases with the increase in the amount of Mg2Si