熱處理合金
　　2024— 因為它的強力、可聯想到“航空”合金去。抗腐蝕性能普通。但機械性良好。只適合熱點結合之點焊、不適用溶焊或接焊。其本身退火後的情況具良好操作性，惟普通至低堅韌度。代表用途如飛機外皮，金屬罩、貨車及飛機架構。
　　6061— 十分良好之抗腐蝕性能及整理效果，加上良好燒焊性及類似軟鋼的強度，是一種普通的多用途合金。良好機械性，在退火後仍能維持一定的“良好”操作性。代表用途飛機降落地板，大小船隻，建築架構配件，儲藏箱，公路牌等。
　　7075— 商用最強力合金之一。普通抗腐蝕性能及機械性能。較低工作性能，只適合點焊用。代表用途如飛機外皮、金屬罩及架。

HEAT-TREATABLE ALLOYS

2024 – Thought of as the “aircraft” alloy because of its strength .the alloy has only fair corrosion resistance but good machinability. Lends itself only to resistance welding as a hot joining process and is not recommended for brazing or soldering, In the annealed state, it has good workability but is only fair to poor in tempers. Typical end uses are aircraft skins and cowls and truck and aircraft structurals.
6061- Very good corrosion resistance and finishability plus excellent weldability and a strength level approximating that of mild steel, this is a popular general-purpose alloy, Machinability is good and ,in the annealed state, its workability carries a high rating, staying at the “good” level if heat-treated without aging. Typical end uses are aircraft landing mats, large and small marine vessels, structural architectural parts, storage tanks and highway signs.
7075 – One of the highest strength, commercially available alloys with fair corrosion resistance and machinabiility. Low workability resistance and welded only by the resistance process.Typically used as aircraft skins, cowls and structures.