摘要
观察和研究了8090Al-Li 合金在弯曲载荷作用下显微裂纹的萌生、扩展和断裂行为,测试了不同状态合金的抗弯性能。结果表明,抗弯强度按 Cast→OA→PA→NA 次序递增,自然时效合金比峰值时效合金的综合性能更好,这归因于最佳的微观组织和晶界状态。实验还表明夹杂物、初生 T_2相和大量T_2相沉淀的亚晶界都是显微裂纹优先形核位置。
Microcrack initiation,growth and fracture behaviors under bend loading wereinvestigated by using three point bend test for an Al-Li alloy.Bend resistance was alsodetemined.Bend resistance decreased in following order:NA→PA→OA→cast.Comprehensiveproperties for the natural ageing condition are better than that for peak ageing condition due toits optimum microstructure and status at grain boundaries.Inclusions,primary T_2 phase andthe subgrain boundaries,where existed a large amount of T_2 precipitates,are all microcrack ini-tiation sites.
基金
国家自然科学基金 58971018
关键词
断裂
显微裂纹
铝锂合金
弯曲试验
aluminium-lithium alloy
fracture
bend
microcrack
