The representative alloy of traditional 6xxx free cutting aluminum alloy is 6262, which was registered in 1960. It is an alloy formed by adding 0.5% Pb and 0.5% Bi to 6061 alloy, which is consistent with 2011
Compared with gold,
6262 T9 aluminum round bar has excellent corrosion resistance, brazing and soldering performance, and anodizing performance. It can be widely used in master cylinder brake piston, connector transmission valve, AC charging valve and parts, pressure parts in automobile, hydraulic equipment and electronic industry, and precision aluminum alloy structural parts with high surface finish in instrument industry.
In 6262 alloy, the elements Pb and Bi with high specific gravity, low melting point and insoluble in aluminum matrix are added, and the price of Bi is high. Therefore, how to prevent the occurrence of specific gravity segregation and improve the yield of Pb and Bi become the primary problem to be solved.
Due to the low melting point and high burning loss of Pb and Bi, it is better to adjust the alloy composition twice in the alloy melting process. Firstly, the elements with less burning loss other than mg, Pb and Bi should be added and the content should be adjusted. After the first exhaust refining, the elements such as Pb, Bi and Mg should be added. After the addition, the alloy should be stirred at least twice. The melting temperature should not be too high, so as to avoid mg, Bi and Mg The burning loss of Pb and Bi is too large. In order to reduce the gas content, a self-designed on-line degassing device is used for on-line degassing and slag removal. During the casting process, the casting speed should be increased to reduce the segregation tumor caused by Pb and Bi.
The addition of Pb and Bi in
6262 T9 aluminum round bar will consume mg, so it is necessary to increase Mg content appropriately.
After 480-500 ℃ extrusion, 528 ± 5 ℃ / 75min solution quenching and 170 ± 5 ℃ / 8h aging, T6 bar can meet the mechanical properties requirements.
When the cold deformation of
6262 T9 aluminum round bar is controlled at 6% ~ 9%, it can meet the requirements of mechanical properties and dimensional tolerance of customers, and also obtain higher quality
