摘要
对表面预制了0.8 mm深、0.5 mm宽裂纹的2A12铝合金进行搅拌摩擦修复,修复后对其修复区显微组织变化规律和力学性能进行了详细研究.结果表明:在合理修复工艺下,实现了裂纹的修复,修复区的平均抗拉强度Rm、屈服强度Re L可达到母材的90.1%和92.2%.修复区存在3个组织变化区,其中修复核心区的晶粒被反复碎化、长大及动态再结晶;热机影响区晶粒具有明显的塑性变形,与晶粒显著长大的热影响区共同构成组织软化区;表面硬度与截面上部硬度曲线相似,截面硬度上部依次高于下部;修复核心区存在大量的小角晶粒,并且内部存在一定密度的位错,在晶粒四周均匀分布细小强化相.
Aviation aluminum alloy 2 A12 containing the prefabricated 0. 8 mm deep and 0. 5 mm horizontal cracks was repaired by the friction stir method,and the microstructure evolution and mechanical properties of the healing zone were observed and analyzed in details. The results showed that the crack repairing is realized in the reasonable healing process,and the tensile strength Rm and the yield strength ReL can reach 90. 1% and 92. 2% of the base metal. The healing zone consists of three different evolution zones,and in the core zone the cracks are repaired by grain fragmentation,growth and recrystallization. The structural softened zone consists of the thermo-mechanically affected zone with obvious plastic deformation and the heat affected zone with obvious grain growth. The surface hardness is similar to that of the upper cross section with the upper section being harder than that of the lower section. The healing core zone consists of many small angle crystals with dislocated lines inside and tiny strengthening phases around.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第1期112-117,共6页
Journal of Northeastern University(Natural Science)
基金
国家自然科学基金资助项目(51335003)
国家自然科学基金青年基金资助项目(51405309).
关键词
搅拌摩擦
2Al2铝合金
裂纹修复
微观组织
力学性能
friction stir
aluminum alloy 2A12
crack repairing
microstructure
mechanical property
