Anode oxidizable high-strength 6xxx series aluminum alloy and preparation method thereof

Abstract

The invention relates to an anode oxidizable high-strength 6xxx series aluminum alloy and a preparation method thereof. The aluminum alloy comprises the following components of 0.7-1.5wt% of Mg, 0.2-0.5wt% of Si, 0.2-0.8wt% of Zn, 0.3-0.7wt% of Cu, 0.2-0.6wt% of Mn, 0.1-0.3wt% of Cr, 0.03-0.12% of Ti, less than or equal to 0. 13wt% of other impurity elements, and the balance Al. The specific preparation method comprises the following steps that pure Al ingots, pure Mg ingots, pure Zn ingots, AlSi intermediate alloy, AlCu intermediate alloy, AlZr intermediate alloy and AlMn intermediate alloy are taken as raw materials, and are put into a smelting furnace in proportion, a melt is subjected to stirring, refining, purifying, degassing and slagging off and standing treatment, then casting is conducted into cast ingots, then extruding is conducted into an aluminum alloy profile according to the extrusion ratio of 15-30:1, and then quenching, T6 heat treatment and anodic oxidation treatmentare conducted. Compared with the prior art, the anode oxidizable high-strength 6xxx series aluminum alloy and the preparation method thereof have the advantages that the Vickers hardness of the 6xxx series alloy extruded profile prepared by the method is greater than 130 HV, the yield strength is larger than 350 Mpa, the elongation rate is larger than 8%, and the surface is uniform in color, and free of the defects such as spots and lines after being subjected to anode oxidation.

Description

technical field [0001] The invention belongs to the field of aluminum alloy materials, and in particular relates to an anodizable high-strength 6xxx aluminum alloy used in appearance parts of electronic products and a preparation method thereof. Background technique [0002] At present, the aluminum alloys used in the manufacture of electronic product appearance parts are still mainly 6-series aluminum alloys. Due to their excellent anodic oxidation performance and good mechanical properties, they are widely used in electronic products such as mobile phone casings, tablet computer casings, desktop computer casings, and liquid crystal display casings. The product shell field is widely used, and it also shows broad application prospects in the field of smart home. However, with the trend of thinner and lighter electronic products, various manufacturers have put forward higher requirements on the performance of housing materials. Traditional 6063 (σs≤220MPa) and 6061 aluminum ...

AI Technical Summary

Problems solved by technology

"The disadvantage of this invention technology is that: the Si content is high, which is very unfavorable to the anodic oxidation effect, and the Mg in the subsequent oxidation and coloring process of the profile 2 The Si phase is easy to cause corrosion pits, resulting in discoloration of patterns; if the content of Cu and Fe is high at the same time, the oxide film of the 6-series alloy is dark and can only be dyed in a dark color; Zn is used as an impurity element At the same time, the extruded profile has not been subjected to solution treatment, and direct artificial aging has failed to fully exert the second phase strengthening effect, so the mechanical properties are low

"The disadvantage of this invention technology is: only Mg and Si form the second phase as the main strengthening phase, although the strength can be significantly improved, but the anodic oxidation performance is relatively limited; the trace elements that inhibit dynamic recrystallization such as Mn, Cr, Zr, etc. Less addition, less retention of deformation strengthening effect during extrusion, resulting in lower profile strength

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