航空铝合金系列材料裂纹扩展性能的温度效应  

Temperature effect on crack propagation properties of aluminum alloys in aircraft

作　　者：李矿[1] 熊峻江[1] 马少俊[2] 陈勃[2] LI Kuang XIONG Junjiang MA Shaojun CHEN Bo(School of Transportation Science and Engineering, Beijiag University of Aeronautics and Astronautics, Beijing 100083, China Beijing Institute of Aeronautical Materials, Beijing 100095, China)

机构地区：[1]北京航空航天大学交通科学与工程学院,北京100083 [2]北京航空材料研究院,北京100095

出　　处：《北京航空航天大学学报》2017年第4期761-768,共8页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(51375033)~~

摘　　要：高低温裂纹扩展性能是航空金属结构损伤容限设计的前提,为此,试验测定了3种系列的6种航空铝合金材料(2024-T351、2397-T8、6061-T651、7050-T7451、7050-T7452和7475-T761)在5种温度环境(-70、-54、25、125和150℃)下的裂纹扩展性能,观测了试验现象,并进行了性能对比分析和疲劳断口扫描电子显微镜(SEM)分析,研究了温度对航空铝合金材料裂纹扩展性能的影响机制,获得了具有工程参考价值的结果与结论:与25℃相比,低温下裂纹扩展阻力系数的对数值降低7%~15%,而高温下却增大5%~23%;低温下裂纹扩展指数增大7%~21%,而高温下却减少5%~34%;氢脆效应和高温氧化作用是导致裂纹扩展速率随温度升高而加快的主要原因。Fatigue properties on crack propagation rate at low and elevated temperatures are the precondi- tion of damage tolerance design for aviation metallic structures. Therefore, in order to determine fatigue prop- erties on crack propagation rate, fatigue tests were performed on six categories of aluminum alloys （ i. e. 2024- T351, 2397-T8, 6061-T651, 7050-T7451, 7050-T7452, 7475-T761 ） at five kinds of temperatures （ - 70 ℃, -54 ℃ , 25 ℃ , 125 ℃ , 150 ℃ ） under constant amplitude loading, and fatigue crack propagation properties were determined and the comparisons between fatigue properties on crack propagation rate at different tempera- tures were carried out. The mechanisms of temperature effect on crack propagation rate were deduced from fractographic studies by using scanning election microscope （SEM）. The results show that, compared with the situation at 25 ℃ , logarithmic crack propagation resistance coefficient decreases by 7% to 15% at low temper- ature, but increases by 5% to 23% at elevated temperature; crack propagation exponent increases by 7% to 21% at low temperature, but decreases by 5% to 34% at elevated temperature, compared with the situation at 25 ℃ ; hydrogen embrittlement and oxidation effects are likely to be the main reasons for more rapid crack propagation with the increasing temperature.

关 键 词：铝合金 裂纹扩展 疲劳 温度 扫描电子显微镜(SEM) 

分 类 号：V252.2[一般工业技术—材料科学与工程]