Mechanical Properties of Al-5.7wt Ni Eutectic Alloy Severely Deformed by Equal-Channel Angular Pressing

摘要

In this study, an Al-5.7wt% Ni eutectic alloy was subjected to severe plastic deformation (SPD) by an equal-channel angular pressing (ECAP) technique. ECAP technique was carried out by using two strain introduction methods, route B_C and route A, at a temperature. It is found that the Al-Ni eutectic alloy specimens after ECAP technique by route B_C and route A methods have very different microstructures which affected strongly the tensile properties of the specimens. Namely, after ECAP technique by route B_C method, the fine Al_3Ni dispersoids of about 300 nm homogeneously dispersed in ex-aluminum matrix and the samples appeared no clear anisotropic in tensile properties, while the eutectic textures containing α-Al and Al_3Ni fibrous dispersoids have highly anisotropy distribution and are proved to have significant anisotropy tensile properties after ECAP technique by route A method. Results of Young's modulus and simultaneous internal friction measured by dynamic mechanical analysis (DMA) were also presented. Based on the experimental results, the fracture mechanism during tensile process of the Al-Ni eutectic alloy by different strain induction methods was discussed.