کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1449967 | 988719 | 2007 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Tension–compression asymmetry in severely deformed pure copper Tension–compression asymmetry in severely deformed pure copper](/preview/png/1449967.png)
In this work, we investigate the tension–compression asymmetry in the flow response of pure copper, severely deformed by a single pass of equal channel angular extrusion (ECAE), and tested afterwards in tension and compression along three orthogonal directions. The tension and compression responses differ in flow stress, hardening rate and transient behavior. The asymmetry in tension and compression responses depends on the direction of straining. Predictions from a microstructurally based hardening law implemented in a viscoplastic self-consistent polycrystal model demonstrate that the tension–compression asymmetry and its anisotropy arise not only from crystallographic texture but also from the directional substructure induced by the severe pre-straining. Slip activity differs in each grain and in each axial test, depending on its crystallographic orientation, orientation relationship with the previously generated substructure and pre-strain history. Asymmetry occurs because tension and compression represent two different types of strain path changes. Consequently, macroscopic deformation is a reflection of the type of strain path change represented by the post-ECAE axial test.
Journal: Acta Materialia - Volume 55, Issue 14, August 2007, Pages 4603–4613