Synergistic role of texture and aging precipitates in tensile mechanical behavior of 2195-T8 Al-Li alloy thick plate
The tensile mechanical behaviors,textures and aging precipitates of 90 mm thick 2195-T8 Al-Li alloy plate at different layer along different direction were investigated. The results show that the alloy possesses the highest yield strength (YS) along rolling direction (RD),but the lowest YS along 45° direction. Along RD,the internal layers (T/2 and 3T/8 layers) has YS 40 MPa higher than the outer layers (T/4 and T/8 layers). However,along 45° direction and transverse direction (TD),there exist little difference in the YS between different layers. The internal layer possesses more deformation textures,the outer layer possesses more recrystallization texture. Due to pre-strain performed on the solid solution along RD,there exists denser T1 precipitate (Al2CuLi) on the {111} slip face with high Schmid factor in the internal layer grains with deformation texture after aging. During the tensile test of the T8-aged alloy along RD,the {111} face of the slip system with high Schmid factor is consistent with the {111} face with high T1 precipitate density. However,during the tensile test along TD and 45° direction,these two types of {111} faces are not fully consistent in some texture grains. Due to the synergistic role of the orientation factor difference caused by texture and the T1 precipitate density difference on different {111} face,the internal layers along RD possesses much higher YS than the outer layers,the alloy also has higher YS,smaller strain hardening rate after yield deformation along RD,and lower difference between YS and UTS (ultimate tensile strength),than the TD and 45° directions.
Al-Li alloytextureprecipitateyield strengthsynergistic role
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维普
