TY - BOOK

T1 - Process development for manufacturing ultrafine-grained aluminum semi-finished-products

AU - Schwarz-Gsaxner, Andreas

N1 - no embargo

PY - 1800

Y1 - 1800

N2 - The grain size of a metal greatly influences its material properties. For this reason, research into nanostructured materials has become increasingly important in recent years. Nanostructured materials can be produced utilizing so-called severe plastic deformation (spd) processes. This thesis describes the development of a machine to produce such materials using a modified Equal Channel Angular Pressing (ECAP) process. The machine enables the production of nanostructured aluminium at room temperature or elevated temperatures through a simulationbased heating system and two hydraulic cylinders for applying a back-pressure during production. The tool represents the most significant challenge in this process. For this reason, a total of four tool concepts were developed and investigated. During the development of the machine, particular attention was paid to incorporating a digital concept into the machine. As a result, a connection between the machine and the associated finite element simulations configured by means of two digital shadows was installed. These enable automatic calculations of the pressing process and the heating process of the material. Additionally, a data storage concept for automatic evaluation of the tests was integrated. The combined influence of the friction conditions and the applied back-pressure on the pressing force, the stress state during forming, the strain homogeneity and the resulting geometry was investigated using finite element simulations. First tests with the aluminium alloy EN-AW-1080 were carried out. Hardness measurements then investigated the influence of different applied back-pressures on the material.

AB - The grain size of a metal greatly influences its material properties. For this reason, research into nanostructured materials has become increasingly important in recent years. Nanostructured materials can be produced utilizing so-called severe plastic deformation (spd) processes. This thesis describes the development of a machine to produce such materials using a modified Equal Channel Angular Pressing (ECAP) process. The machine enables the production of nanostructured aluminium at room temperature or elevated temperatures through a simulationbased heating system and two hydraulic cylinders for applying a back-pressure during production. The tool represents the most significant challenge in this process. For this reason, a total of four tool concepts were developed and investigated. During the development of the machine, particular attention was paid to incorporating a digital concept into the machine. As a result, a connection between the machine and the associated finite element simulations configured by means of two digital shadows was installed. These enable automatic calculations of the pressing process and the heating process of the material. Additionally, a data storage concept for automatic evaluation of the tests was integrated. The combined influence of the friction conditions and the applied back-pressure on the pressing force, the stress state during forming, the strain homogeneity and the resulting geometry was investigated using finite element simulations. First tests with the aluminium alloy EN-AW-1080 were carried out. Hardness measurements then investigated the influence of different applied back-pressures on the material.

KW - ECAP

KW - SPD

KW - ALUMINIUM

KW - FEA

KW - DIGITIZATION

KW - DIGITAL SHADOW

KW - ECAP

KW - SPD

KW - FEM

KW - DIGITAL SHADOW

KW - DIGITALISIERUNG

M3 - Doctoral Thesis

ER -