Preparation method of low-cost high-performance 6xxx aluminum alloy super-thick plate

The invention belongs to the technical field of aluminum alloy processing, and particularly relates to a preparation method of a low-cost high-performance 6xxx aluminum alloy super-thick plate. According to the method, blank cutting, surface cleaning, multi-layer blank assembling and vacuum seal welding are carried out on a 6xxx aluminum alloy sheet continuous casting blank, then warm rolling welding is carried out, and in other words, the 6xxx aluminum alloy super-thick plate is prepared by promoting interface metal to be subjected to solid-phase combination through thermal deformation under the vacuum condition. And finally, the comprehensive performance of the aluminum alloy thick plate is further improved through solution treatment and aging strengthening. According to the method, the sheet continuous casting billet produced on a large scale is adopted as the base metal, the performance is good, defects are few, the yield is high, the cost is low, the long-time homogenizing annealing process is not needed