| 摘要: | 以金屬空心球法製備之多孔鋁，內部孔隙為封閉式結構，具有密度低、比強度高、抗壓縮性能好之優點，吸能性為商用泡沫鋁的數倍，極具發展潛力，可應用於抗彈或抗爆領域。A201鋁合金(Al-4.5Cu-0.3Mg-0.7Ag)為鑄造型鋁合金中強度最高者，主要強化方式為析出強化熱處理，可藉由強化相Ω與θ′的析出，提高合金機械性質，實務上依用途不同，可施以T4自然時效、T6頂時效、T7過時效等熱處理方式。本研究利用Φ2mm316L、Φ4mm316L、Φ4mm4605金屬空心球，以壓力滲透鑄造法製備A201多孔鋁，經固溶水淬後，分別施以T4自然時效(RT*4day)、T6頂時效(155°C*20hr)、T7過時效(185°C*5hr)等不同熱處理製程，探討空心球與熱處理對A201多孔鋁微結構與機械性質(壓縮、硬度)之影響。
結果顯示，鑄態多孔鋁之空心球壁微結構，316L為沃斯田鐵，4605為細波來鐵，而鋁基地微結構皆由α-Al+富鐵相+少量Al2Cu共晶相所組成;經時效處理後，由於Ω相與θ′相之析出強化效果，鋁基地硬度明顯提升，又以T6頂時效處理之升幅最大。機械性質部分，由於4605球硬度高，所含其之多孔鋁，壓縮性質均優於含316L球之多孔鋁。除外，降低空心球之尺寸，對壓縮性質亦有正向性提升效果。綜上所述，含Φ4mm4605空心球之多孔鋁，施以T6頂時效處理後，其平台應力(σpl)與單位能量吸收值(W)分別高達190MPa與112J/cm3，乃為目前蒐集文獻中，具最優秀壓縮性質之多孔鋁。
;Porous aluminum prepared by the metal hollow sphere method possesses a closed cell structure, offering advantages such as low density, high specific strength, and excellent compression properties. Its energy absorption capacity is several times that of commercial aluminum foam, making it highly promising for applications in ballistic or blast-resistant fields. A201 aluminum alloy (Al-4.5Cu-0.3Mg-0.7Ag) is the highest-strength casting aluminum alloy, primarily strengthened through precipitation strengthening heat treatment. This process involves the precipitation of strengthening phases Ω and θ′ to enhance the mechanical properties of the alloy. In practical applications, different heat treatment methods, such as T4 natural aging, T6 peak aging, and T7 overaging, can be applied depending on the specific requirements.
In this study, A201 aluminum alloy foam was prepared using Φ2mm 316L, Φ4mm 316L, and Φ4mm 4605 metal hollow spheres through pressure infiltration casting. After solution treatment and water quenching, various heat treatment processes, including T4 natural aging (RT*4day), T6 peak aging (155°C*20hr), and T7 overaging (185°C*5hr), were applied to investigate the influence of hollow spheres and heat treatment on the microstructure and mechanical properties (compression and hardness) of A201 aluminum alloy foam.
The results show that the microstructure of the as-cast porous aluminum consists of austenite for 316L and fine pearlite for 4605 in the hollow sphere walls, while the aluminum matrix microstructure is composed of α-Al, iron-rich phases, and a small amount of Al2Cu eutectic phases. After aging treatment, the precipitation strengthening effects of Ω and θ′ phases significantly increase the hardness of the aluminum matrix, with the most significant improvement observed in the T6 peak aging treatment. In terms of mechanical properties, due to the higher hardness of 4605 spheres, porous aluminum containing 4605 spheres exhibits superior compression properties compared to those containing 316L spheres. Furthermore, reducing the size of the hollow spheres has a positive effect on compression properties.
In summary, aluminum alloy foam containing Φ4mm 4605 hollow spheres, subjected to T6 peak aging treatment, achieves a plateau stress (σpl) of up to 190MPa and a specific energy absorption value (W) of 112J/cm3. This represents the best compression properties among the literature-reviewed porous aluminum materials. |
