- 學位論文
添加Sc、Zr合金元素對5456鋁合金機械性質與顯微結構的影響
Mechanical Properties and Microstructure of two 5456 Aluminum Alloys Modified by Sc and Zr Additions
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摘要
本文旨在探討兩種含鈧、鋯元素之5456鋁合金(M5A；Al - 5.4Mg - 0.1Sc - 0.1Zr；M5B：Al - 6.5Mg - 0.1Sc - 0.1Zr，wt. %)於直接冷卻鑄造法熔煉，再經由熱擠製處理，可獲致機械性質良好之細晶組織。將材料利用不同的冷加工量(軋延)與不同熱處理，探討材料於各階段製程中，退火熱處理的溫度與時間對機械性質的影響。M5A與M5B材經冷加工後，其最佳安定化退火溫度為200 oC持溫60分鐘。 在高溫環境下，其拉伸機械性質亦有優異的表現，探討溫度於200 ~ 500 oC間，應變速率為1 x 10-2 s-1的高速超塑性，其於500oC，最大的伸長率可達1000%以上。 其5456鋁合金經鈧、鋯元素添加後，並配合熱機處理製程，使之具有優異的機械性質，對工業界上的應用有實質上的幫助。
關鍵字
超塑性並列摘要
This study investigated the two 5456 aluminum alloys (M5A: Al - 5.4Mg - 0.1Sc - 0.1Zr; M5B: Al - 6.5Mg - 0.1Sc - 0.1Zr, wt. %) that modified by Sc and Zr elements were fabricated by hot extrusion. The studied alloys exhibited an excellent mechanical properties and fine grain structure after vertical direct chill cast (VDC). The effects of temperature and time on the mechanical properties of the materials were investigated during each stage of the thermo mechanical treatment process with different amounts of cold worked. The best condition of stabilization annealing is 60 minutes at 200 oC after cold worked. They were also exhibited excellent tensile properties in the higher temperature environment. And the tensile tests were carried out at temperature of 200 to 500 oC and strain rate of 1 x 10-2 s-1. The maximum elongation to failure of ~1000 % was obtained at the strain rate of 500 oC and 1 x 10-2 s-1. The 5456 aluminum alloys modified by Sc and Zr elements with thermo mechanical treatment process exhibited excellent mechanical properties for high strength weld structure applications. The two alloys were useful and helpful for industry-wide practical applications.
並列關鍵字
Superplasticity參考文獻
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