6061鋁合金（Al-1.0Mg-0.6Si）具高比強度與抗腐蝕性佳等優點，目前已廣泛應用於交通運輸及建築工件上。6061為熱處理型合金，容易隨時間而析出強化，導致後續加工時難以成形。復原（Reversion）處理為一種軟化材料而提高加工性質的處理方法，利用瞬間高溫熱處理，使材料達到性質回復以利加工成形之目的。
實驗將6061先處以固溶處理，待硬度穩定後施以不同復原處理溫度（140~320℃-60sec，每30℃為一間隔），探討材料之性質回復效果；此外，復原處理後材料特性亦屬考量重點，故對復原處理後人工時效（T6）之試片進行硬度及拉伸測試。
實驗結果顯示，復原處理後硬度方面，140～170℃之硬度未有明顯變化，其原因可能為復原溫度未達可供分解β"相核之溫度；200~260℃之硬度較未復原處理者低，推測是析出強化相（β"）核的分解，使材料產生性質回復；290℃使硬度上升，推論材料以析出β"主導；320℃硬度微降，推測是材料析出稍過時效相β'，造成材料的退化現象。拉伸方面，對260~320℃與未復原處理者比較，發現260℃、320℃之UTS較未復原處理者低，推測分別是β"相核的分解與β'析出所致，290℃有最高的YS，則可能為β"析出導致，延性隨復原溫度升高而下降，推測材料受析出核分解與β"、β'之析出所影響。
復原後T6處理之硬度量測，140~260℃尚接近正T6硬度值，而320℃則無法有效回升，造成如此差異的原因，推測是320℃復原處理將尚存在材料之固溶原子，與分解β"相核所固溶的原子，以稍過時效相β'再析出，以致後續T6處理無足夠的固溶原子以形成β"提升材料硬度。拉伸方面，260℃拉伸性質幾乎與正T6相同，而320℃之拉伸性質則與上述硬度趨勢相同。

6061 aluminum alloy (Al-1.0Mg-0.6Si) is widely used in many industries such as transportation and architecture due to its high strength to weight ratio and corrosion resistance. 6061 is a heat treatable alloy and will increase the strength over time by precipitation hardening. After aging hardening, 6061 is hard to be formed. Nowadays, reversion is one kind of material softening method to enhance formability, using instantaneous high temperature heat treatment to reach the goal of reversing properties.
In this study, 6061 is treated with different reversion temperatures (140~320℃-60sec, per 30℃) after solution heat treatment and aging to stable in order to discuss the effects of property reversion. Moreover, since the material properties after reversion treatment will be taken into consideration, the hardness and tensile tests of 6061 specimen with T6 condition after reversion will be conducted.
The results of hardness test after reversion show that the hardness of 6061 specimen with reversion temperatures (140~170℃) does not change obviously. It’s considered that the reversion temperatures are not high enough to dissolve the β" nuclei. The hardness with reversion temperatures (200~260℃) is lower than that of 6061 specimen without reversion probably due to property reversion caused by dissolving the nuclei of precipitation hardening phase β". However, the hardness with 290℃-reversion increases due to the dominant precipitation β". The hardness with 320℃-reversion is slightly lower than that of 6061 specimen without reversion possibly due to the over-aged phase β' leading to the regression of material. In tensile properties, the UTS of reversion temperatures of 260℃ and 320℃ is lower than that of 6061 specimen without reversion. This may be respectively caused by the dissolution of β" nuclei and the precipitation of β'. The YS with 290℃-reversion is the highest among the tensile test. It can be ascribed to the precipitation of β". The ductility (260~320℃) will reduce with increasing the reversion temperature. It is presumably related to the dissolution of β" nuclei and the precipitation of β" and β'.
In terms of hardness test after reversion and T6 treatment, the hardness value with reversion temperature (140~260℃) is close to that of normal T6 but 320℃. The reasonable speculation causing this difference is that 320℃-reversion will prompt the solute atoms originally staying in matrix and dissolved by the β" nuclei to precipitate in β'. With the precipitation of β', it’s not easy to form β" while T6 treatment to reinforce the hardness due to the shortage of solute atoms. The tensile properties with 260℃ is almost the same as that of normal T6. Nevertheless, 320℃ has the same trend with hardness.

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