Effect of strain-path change on the anisotropic mechanical properties of a commercially pure aluminum

38th Risø International Symposium on Materials Science

Sun, P.L.^1 ; Huang, S.J.^2

Department of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung

80424, Taiwan^1

Department of Materials Science and Engineering, Feng Chia University, Taichung

40724, Taiwan^2

关键词: Anisotropic mechanical properties;    Anisotropic response;    Commercially pure aluminum;    Compressive loading;    Equal channel angular extrusion;    Mechanical behavior;    Mechanical response;    Orthogonal directions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/219/1/012040/pdf
DOI  :  10.1088/1757-899X/219/1/012040

来源: IOP

【 摘 要 】

Samples of commercially pure aluminum were subjected to equal channel angular extrusion (ECAE) using a 90°square die by routes A and C, where the specimens are not rotated and are rotated 180°between extrusion passes, respectively. Qualitatively similar anisotropic responses under compressive loading along the three orthogonal directions of the ECAE billet are seen in both cases. The plastic anisotropy is related to the effect of strain-path change, namely that different slip activities are induced for specimens loaded along different directions with respect to the last ECAE pass. The anisotropic mechanical behavior is more evident in the sample deformed by route C. Considering the shear patterns imposed in each ECAE route, the characteristics of dislocations introduced in ECAE should affect the mechanical response in post-ECAE loading. It is suggested that during the ECAE process, dislocations on fewer slip systems are activated in route C than in route A, and therefore, a stronger plastic anisotropy results in this sample. The as-ECAE specimens were also heat treated to achieve a recovery-annealed state. The plastic anisotropy persists in the annealed specimens to slightly reduced extent, which can be ascribed to partial annihilation of preexisting dislocations.