通过金相显微、透射电子显微、电子拉伸和剥落腐蚀实验研究了7050铝合金板材蠕变时效与人工时效的微结构及性能。结果表明:蠕变时效过程中施加的应力使板材不断产生变形,为η′析出相提供了大量形核点,析出相尺寸更加细小,特别是晶界无沉淀带较人工时效明显变窄,晶界析出相不连续。与人工时效相比,蠕变时效试样的抗拉强度和抗剥落腐蚀性能略有提高。
Microstructures and properties of 7050 aluminum alloy sheet after creep aging and artificial aging were studied by optical microscopy(OM),transmission electron microscopy(TEM),electronic tensile test and exfoliation corrosion test respectively.The results show that the loaded stress during creep aging generates continuously deformation,which provides a large amount of nucleation points for the precipitation of the η′ particles.The size of the η′ particles is smaller than that of the artificial aging.Especially,the precipitation free zone is narrower than that of the artificial aging,and grain boundary precipitates are discontinuous.The tensile strength and the resistance to exfoliation corrosion of the creep aging samples are better than those of the artificial aging.