Al-Cu-Mg-Ag合金為一高強度鋁合金，其強化相主要為Ω與θ’，由文獻中知，當Cu/Mg比在5～10之間，有利於Ω相的析出，加入適量的Ag時，更可促進Ω相於鋁基地的主要滑動面{111}α上析出，因此可提升材料機械強度。Mg、Ag原子於時效期間的聚集，是Ω相的成核點；而θ’相的析出則與差排息息相關，所以θ’析出行為會受加工所影響。故本研究探討主題為自然時效與冷加工對Al-4.6Cu-0.5Mg-0.5Ag微結構及機械性質之影響。
本研究針對Al-4.6Cu-0.5Mg-0.5Ag施以不同時間的自然時效（0～24小時）及不同的冷加工量（6、13、23、45％），而後於185℃下施行5小時人工時效，利用光學顯微鏡（OM）、導電度（％IACS）、微差掃瞄熱分析儀（DSC）、硬度試驗、拉伸試驗、掃瞄式電子顯微鏡（SEM）、穿透式電子顯微鏡（TEM），探討微結構變化與材料機械性質之對應關係，根據結果以瞭解自然時效處理與冷加工量對Al-4.6Cu-0.5Mg-0.5Ag機械性質之影響。
由結果可知，Mg、Ag原子能於自然時效初期（五小時內）快速聚集產生Cluster，但由於其在高溫下聚集的速度更快，因此在高溫熱處理後，合金在強化相的析出量及機械性質上並無明顯差異。其差別僅於：若經自然時效處理，能提升合金於人工時效時的析出硬化速率。
而固溶後隨即冷加工，由於缺陷的生成，阻礙了Mg-Ag的聚集，在人工時效時，能減少Ω相析出，同時由於差排變多，使得θ’析出量較無冷加工的多。加工量越大，抑制Ω相析出效果越顯著，但相對θ’相析出越多，Ω相析出減少雖造成強度降低，但由於加工硬化效果顯著，使得硬度及強度皆有所提升，但不利於延性。

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