Producing high strength aluminum alloy by combination of equal channel angular pressing and bake hardening

• High strength UFG AA6061 aluminum was produced by combination of ECAP and bake hardening processes.
• The microstructures of the ECAP-processed samples were characterized by XRD and EBSD.
• Average grain size of 20 µm was refined to 212 nm after 8 passes of ECAP.
• Bake hardenability of 110 MPa and yield stress of 330 MPa were obtained after combination of 8 passes of ECAP and bake hardening.

A combination of severe plastic deformation by equal channel angular pressing (ECAP) and bake hardening (BH) was used to produce high strength ultrafine-grained AA6061 aluminum alloy. 2, 4 and 8 passes of ECAP were performed, and the bake hardenability of samples was tested by 6% pre-straining followed by baking at 200 °C for 20 min. The microstructures obtained for various passes of ECAP were characterized by XRD, EBSD, and TEM techniques. The microstructures were refined from an average grain size of 20 µm to 212 nm after 8 passes of ECAP. Maximum bake hardenability of 110 MPa, and final yield stress of 330 MPa were obtained in the specimens processed by 8 passes of ECAP.