Aluminum-clad hard aluminum and super-hard aluminum have high strength but are not resistant to corrosion. To improve their corrosion resistance, a layer of high-purity aluminum or 1% zinc-aluminum is often coated on hard aluminum and super hard aluminum surfaces. Alloy layer, so called aluminum. Aluminum plate with aluminum coating is also called aluminum plate.
When the aluminum layer is covered, the strength decreases. 2) The solution treatment temperature range is narrow, less than this temperature can not exert the maximum strengthening effect, and beyond the upper limit temperature, there may be the occurrence of the grain boundary "over" may cause the grain aggregation to be destroyed. 3) The tendency of welding cracks is large and it is difficult to use the welding method