航空及模具用高強力鋁合金AA7075和2024之開發

Development of High Strength Aluminum Alloys AA7075 and 2024 for Aircraft and Dies

石漢正(H.C. Shih) ； 劉欽仁(C.J. Liu) ； 詹金生(C.S. Chan) ； 許國峰(K.F. Hsu)

《鑛冶：中國鑛冶工程學會會刊》 48卷1期 (2004/03) Pp. 35-51

https://doi.org/10.30069/MM.200403_48(1).0004

摘要

高強力鋁合金AA7075和2024由於合金濃度高，致鋁胚於澆鑄期間常因熱應力過大而發生冷脆裂的現象；針對這個難題，本研究藉助於破損分析、熱傳和應力模型之解析以及澆鑄輔助設施之開發，不僅從材質上增強鋁胚對破裂之阻抗，而且在力學上亦緩和鋁胚內外之溫度梯度；如此雙管齊下，使得所鑄鋁胚非但不再冷裂，而且不需額外的應力退火處理。此外，本研究更進一步利用熱分析法和熱軋模擬試驗，開發出鋁板片之最佳熱機處理量產製程，不僅增加強化相的數量，而且也克服這些板片在固溶升溫和淬火過程中易發生的表面氣泡和嚴重扭曲等問題，使其無論在機械性質或外觀品質方面，皆可達到國際之水準。

關鍵字

澆鑄 ； 熱應力 ； 破損分析 ； 數學模型 ； 熱分析法 ； 熱機處理 ； 氣泡 ； 扭曲

並列摘要

High strength AA7075 and 2024 aluminum alloys with high concentration of alloy elements often cracked in brittleway during casting because of extremely large induced thermal stress. To solve this problem, failure analysis, thermal and stress analysis, and casting facility developments have been undertaken in this study. The resistance of materials to fracture was thus increased and the temperature gradient was alleviated as well. Consequently, the cold cracking of slabs was eliminated completely and the stress relief annealing needed before also was canceled. Moreover, the optimal processes of thermo-mechanical treatment for the mass production of aluminum plates have been further developed through thermal analysis and hot-rolling simulation tests. The amount of strengthening phases was thus increased. The bubbles on surfaces and the distortion in shape, which took place at the stages of heating and quenching these plates during solid solution treatment, respectively, were overcome at the same time. As a result, not only mechanical properties but also the appearance of the plates can meet international standards.

並列關鍵字

Casting ； Thermal Stress ； Failure Analysis ； Mathematical Model ； Thermal Analysis ； Thermo-mechanical Treatment ； Bubble ； Distortion