發(fā)布時間：2018-08-07 18:19

【摘要】：通過對峰時效與T7951二次時效7055鋁合金力學性能測試、微觀組織與斷口分析,研究了顯微組織、基體析出相、晶界析出相與晶界無沉淀析出帶對材料強度與斷裂韌性的影響,并分析了斷裂機理。研究表明T7951二次時效產(chǎn)生的位錯強化、細晶強化效應與基體內出現(xiàn)平衡η相導致的弱化作用之間的競爭機制導致材料強度較峰時效損失不大;晶界析出相的團聚粗化是造成二次時效7055鋁合金斷裂韌性提高的主因;7055鋁合金室溫拉伸斷口表明斷裂機理為韌脆混合型斷裂,二次時效較峰時效表現(xiàn)出更強的韌性斷裂特征。
[Abstract]:The effects of microstructures, matrix precipitates, grain boundary precipitates and grain boundary precipitates on the strength and fracture toughness of 7055 aluminum alloy with peak aging and T7951 secondary aging were studied. The fracture mechanism is also analyzed. The results show that the competition mechanism between the dislocation strengthening, the fine grain strengthening effect and the weakening effect caused by equilibrium 畏 phase in the matrix makes the strength of T7951 less than that of the peak aging. The agglomeration coarsening of precipitated phase at grain boundary is the main reason for the increase of fracture toughness of 7055 aluminum alloy after secondary aging. The tensile fracture at room temperature indicates that the fracture mechanism is ductile-brittle mixed fracture, and the secondary aging shows a stronger ductile fracture characteristic than peak aging.
【作者單位】： 沈陽航空航天大學機電工程學院;沈陽航空航天大學航空制造工藝數(shù)字化國防重點學科實驗室;
【基金】：遼寧省自然科學聯(lián)合基金(2013024012)
【分類號】：TG146.21;TG166.3
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本文編號：2170926