Microstructures, Mechanical Properties and Strengthening Mechanisms of cast Cu-Al Alloys Processed by Cryorolling

In the present work, the cast structures of Cu-4.5wt% Al alloy was homogenized by annealing at 800 C for 4 h. The samples were kept under LN2 before and during the rolling process in each pass to maintain a constant LN2 temperature. Mechanical properties were evaluated by the tensile test. Microstructural analysis was carried by optical microscopy and TEM analysis. The maximum yield strength (YS) of the 75 % cryorolled samples of Cu-4.5wt% Al alloy was found to be 786 MPa with a ductility of 4.8 %. This is due to the formation of ultrafine grains and nano -twins possibly play the pivotal role for the improved YS and ductility.