二次时效7055-T7951铝合金微观组织及力学性能
发布时间：2018-08-07 18:19
【摘要】：通过对峰时效与T7951二次时效7055铝合金力学性能测试、微观组织与断口分析,研究了显微组织、基体析出相、晶界析出相与晶界无沉淀析出带对材料强度与断裂韧性的影响,并分析了断裂机理。研究表明T7951二次时效产生的位错强化、细晶强化效应与基体内出现平衡η相导致的弱化作用之间的竞争机制导致材料强度较峰时效损失不大;晶界析出相的团聚粗化是造成二次时效7055铝合金断裂韧性提高的主因;7055铝合金室温拉伸断口表明断裂机理为韧脆混合型断裂,二次时效较峰时效表现出更强的韧性断裂特征。
[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.
【作者单位】： 沈阳航空航天大学机电工程学院;沈阳航空航天大学航空制造工艺数字化国防重点学科实验室;
【基金】：辽宁省自然科学联合基金(2013024012)
【分类号】：TG146.21;TG166.3
，
本文编号：2170926
[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.
【作者单位】： 沈阳航空航天大学机电工程学院;沈阳航空航天大学航空制造工艺数字化国防重点学科实验室;
【基金】：辽宁省自然科学联合基金(2013024012)
【分类号】：TG146.21;TG166.3
，
本文编号：2170926
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