服役经历对7N01铝合金断裂力学性能的影响

发布时间：2018-04-15 15:59

本文选题：N铝合金 + 断裂力学　；参考：《东北大学学报(自然科学版)》2017年10期

【摘要】：材料在服役过程中的可靠性和耐久性是结构安全评估的基础,针对某型高速列车上服役多年的7N01铝合金材料,进行实验室空气环境下断裂力学性能参数测试,并分析服役前后疲劳裂纹扩展行为差异.结果表明:服役经历促使材料的各项断裂力学性能退化,呈规律性下降趋势;服役材料稳态疲劳裂纹扩展阶段da/d N-ΔK关系曲线呈折线现象,分段拟合方法能够精确描述其疲劳裂纹扩展行为.微观形貌的结果显示:服役后7N01铝合金的疲劳裂纹早期扩展区、稳定扩展区和快速断裂区的断裂表面依次为脆性断裂特征、塑性疲劳条带和脆性疲劳条带混合模式及沿晶和穿晶的混合断裂形貌.
[Abstract]:The reliability and durability of materials in service are the basis of structural safety evaluation. The fracture mechanical properties of 7N01 aluminum alloy materials which have been in service for many years on a high speed train are tested in laboratory.The difference of fatigue crack growth behavior before and after service is analyzed.The results show that the service experience leads to the degradation of the fracture mechanical properties of the materials, and the curve of da/d N- 螖 K in the steady fatigue crack growth stage of the service materials shows a broken line phenomenon.The piecewise fitting method can accurately describe the fatigue crack growth behavior.The results of microscopic morphology show that the fracture surfaces of the fatigue crack growth zone, the stable growth zone and the fast fracture zone of 7N01 aluminum alloy after service are brittle fracture characteristics in turn.The mixed mode of plastic fatigue strip and brittle fatigue band and the mixed fracture morphology of intergranular and transgranular.
【作者单位】：东北大学航空动力装备振动及控制教育部重点实验室;沈阳建筑大学机械工程学院;
【基金】：国家自然科学基金重点资助项目(51335003);国家自然科学基金资助项目(51675353) 辽宁重大装备制造协同创新中心资助项目教育部长江学者创新团队计划项目(IRT_15R45) 沈阳市科技局计划项目(F16-096-1-00)
【分类号】：TG146.21

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