Ultrasonic Assisted Incremental Equal Angular Channel Pressing Process of AA 6063

Abstract

Industrial usage of ultrafine-grained materials is not common because of their high manufacturing cost of unconventional processing techniques for serial manufacturing. There is a need to increase process efficiency and decrease manufacturing costs for industrial usage of severe plastic deformation methods to manufacture ultrafine-grained materials. Previously, ultrasonic systems and incremental feeding of materials are used to increase process efficiency. In this experimental study, the ultrasonic system is adapted to an incremental equal angular channel pressing method, called ultrasonic-assisted incremental equal channel angular pressing (UI-ECAP). As a reference material of this new system, AA 6063 is selected. Two passes I-ECAP are applied to the initial material with and without ultrasonic vibrations. The microstructure and mechanical results are investigated for both specimen groups. According to the observations, grain size differences throughout the microstructure decrease with the application of ultrasonic impulses during the deformation. However, UI-ECAP results in smaller and more equiaxed grain geometry and finer precipitates observed in transmission electron microscope (TEM) analysis. According to the hardness mapping results, UI-ECAPed sample shows more homogenous hardness distribution than I-ECAPed sample. The yield strength and ultimate tensile strength of the specimen after two passes of UI-ECAP are higher in comparison with the I-ECAP.