冷軋純鋁之再結晶特性研究

Recrystallization of Cold Rolled Pure Aluminum

蕭詠禎(Yung-Jen Hsiao)

指導教授 ： 陳貞光

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2012年)

https://doi.org/10.6841/NTUT.2012.00046

摘要

本實驗使用高純度鋁(99.999%)經冷軋10%、30%、50%、70%、90%後，分別進行100°C、200°C、300°C與400°C的靜態再結晶熱處理。在未經熱處理、冷軋達50%以上的試片中，顯微組織開始有些許靜態再結晶的出現，熱處理一開始進行動態回復時，差排往晶界附近移動，形成許多低角度晶界，接著新的晶粒在晶界附近開始形成。隨著熱處理溫度上升，晶粒逐漸粗化，此時由背向散射繞射分析測得晶粒的集合組織，在退火初期由{001}<100>立方織構轉變為相對混亂的隨機集合組織，立方織構的比例由14.8%降為0%；當再結晶完成時，立方織構的集合組織再度增強。而晶粒開始粗化後，才又回到隨機的集合組織。但當冷軋量提高到70%以上時，晶粒粗化達到一臨界值時，晶粒仍會再度回到立方織構，顯示在立方織構中，晶粒間的晶界能相對較低，也代表以立方織構存在的晶界原子重合性較佳，因此大的晶粒傾向以立方織構方向吞食其他鄰近的晶粒所致，以保有更穩定的晶界。

關鍵字

冷軋 ； 退火 ； 動態回復 ； 再結晶 ； 織構

並列摘要

In this study, 99.999% 5n high-purity aluminum is cold-rolled by 10%, 30%, 50%, 70%, and 90%. The materials are then annealed at 100 °C, 200 °C, 300 °C, and 400 °C. Without annealing, materials cold rolled by 50% or more demonstrate dynamic recrystallization. Dynamic recovery is observed by migration of mobile dislocations toward the grain boundaries. Such activities increase the amount of low-angle grain boundaries. Recrystallized grains are then observed to form primarily at the grain boundaries with increasing annealing temperature. EBSD observations find that the {001} <100> cube texture gradually rotates toward random texture at initial recrystallization stage. The cube texture decreases from 14.8 % to 0%. When recrystallization completes, the structures rotate back to the cube texture. In the coarsening stage, the grains grow with time and relatively random texture is again obtained. It is observed that, in the cold-rolled 70% aluminum, after grain coarsening reaches a critical value, the grains return to bear cube texture. The grain boundary energy apparently is lower for cube textured grains possibly due to the coherence among between the grains. It stabilizes the grain structures by lowering the boundary energies.

並列關鍵字

Cold rolled ； Annealing ； Dinamic recovery ； Recrystallization ； Texture

參考文獻

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