Exami̇nati̇on of equal channel angular pressi̇ng method and appli̇cati̇on to 6063 alumi̇ni̇um alloy

Severe Plastic Deformation (SPD) processes are metal forming processes in which an ultra-large plastic strain is applied to metal mass to form ultra fine grains. The main aim of the APD process is to produce high strength and lightweight parts that are compatible with the environment. The Equal Channel Angular Pressing (ECAP) method is a method of grain refinement by the Severe Plastic Deformation (SPD) process in which materials with grain structure at submicron and nano size are produced at low temperatures. Superior physical and mechanical properties are obtained in ECAP applied materials. The materials subjected to ECAP treatment show high strength, good ductility and superplastic behavior at low temperatures. In the process, the material is pressed into a mold consisting of two channels having the same shape and cross-sectional dimension. ECAP process includes various process parameters such as die angles, pressing speed, pressing temperature, process roots, number of passes, back press and material to be pressed. There are 6 main sections in this study. In the first part of the work, general information about severe plastic deformation and equal channel angular pressing method is given. In the second part, severe plastic deformation processes, in the third part, equal channel angular pressing method and process parameters, in the fourth part, alternative ECAP methods and parallel channel ECAP method are explained. In the fifth chapter, explanations were made about Aluminum and Alloys. In the sixth part, the material to be applied to the ECAP test, ECAP mold, ECAP test, pressing force, hardness measurement, test results and suggestions were examined. In the experimental section, a new mold design with different properties than previous ECAP molds was used. Information has been given on the materials used during the preparation of the mold and the preparation of the sample. The mold designed for ECAP process consists of channels with 90° channel angle and 0° angle of curvature. Route A was used for during the application process. The process was carried out at a punching speed of 10 mm / min without applying any temperature to the mold and sample. In this new mold made, 6063 Aluminum alloy material measuring 10 mm x 10 mm x 54 mm applied 2 consecutive pressing processes. The Brinell hardness values of the first sample, the first post-press, and the second post-press were measured and evaluated. In addition, the force applied during 1st pressing and the force applied during 2nd pressing are determined and compared. Keywords: ECAP, SPD, ultra fine grain, 6063 aluminium alloy, hardness, mechanical features