TY - THES

T1 - Natural aging of aluminum alloy 6082

AU - Engelhart, Maximilian Karl

N1 - embargoed until 04-09-2023

PY - 2018

Y1 - 2018

N2 - The aim of this thesis is to evaluate the effect of different heat treatments (pre aging) and pre deformation on the properties of 5 different aluminum alloys (6261, 6082 low alloyed, 6082 high alloyed, 6060 and 6066). The different properties investigated such as aging response, precipitation behavior, mechanic and corrosion properties were microstructure (TEM), corrosion behaviour and mechanical testing by tensile specimen. The further understanding of the kinetics of natural aging and its influence on artificial aging can help to further improve the different heat treatments applied in aluminium industry. Natural aging behavior is important because it has a big influence on the kinetics of Artificial Aging (AA). Natural aging proceeds through the decomposition of solid solution. Usually the decomposition stops when the first Guinier-Preston (GP) zones are formed. Formation of zones is common for many types of natural aging in different metals. The first separation of phases normally appears during natural aging. If there is a high supersaturation of atoms and vacancies the formation of GP zones rapidly proceeds. However this is not wanted in some cases. Therefore methods need to be developed to inhibit effects of natural aging. Therefore it is necessary to analyze the effect of different heat treaments on the final microstructure by TEM. Also mechanical properties and corrosion are greatly affected by the microstructure. Two different pre aging treatments with 30 min at 100°C and 3 hours at 140°C were applied and combined with different natural aging times between solution heat treatment with quenching, pre aging and artificial aging. The duration of artificial aging was 9 and 14 hours at 160°C. It can be observed that the microstructure is strongly influenced by the heat treatment (pre aging in this case). The aim of this thesis is to further investigate the natural aging behavior of aluminium alloy 6082 since this alloy is heavily used in automotive industry.

AB - The aim of this thesis is to evaluate the effect of different heat treatments (pre aging) and pre deformation on the properties of 5 different aluminum alloys (6261, 6082 low alloyed, 6082 high alloyed, 6060 and 6066). The different properties investigated such as aging response, precipitation behavior, mechanic and corrosion properties were microstructure (TEM), corrosion behaviour and mechanical testing by tensile specimen. The further understanding of the kinetics of natural aging and its influence on artificial aging can help to further improve the different heat treatments applied in aluminium industry. Natural aging behavior is important because it has a big influence on the kinetics of Artificial Aging (AA). Natural aging proceeds through the decomposition of solid solution. Usually the decomposition stops when the first Guinier-Preston (GP) zones are formed. Formation of zones is common for many types of natural aging in different metals. The first separation of phases normally appears during natural aging. If there is a high supersaturation of atoms and vacancies the formation of GP zones rapidly proceeds. However this is not wanted in some cases. Therefore methods need to be developed to inhibit effects of natural aging. Therefore it is necessary to analyze the effect of different heat treaments on the final microstructure by TEM. Also mechanical properties and corrosion are greatly affected by the microstructure. Two different pre aging treatments with 30 min at 100°C and 3 hours at 140°C were applied and combined with different natural aging times between solution heat treatment with quenching, pre aging and artificial aging. The duration of artificial aging was 9 and 14 hours at 160°C. It can be observed that the microstructure is strongly influenced by the heat treatment (pre aging in this case). The aim of this thesis is to further investigate the natural aging behavior of aluminium alloy 6082 since this alloy is heavily used in automotive industry.

KW - Natural aging

KW - 6xxx Al-Alloy

KW - heat treatment

KW - TEM

KW - corrosion

KW - microstructure

KW - Natürliche Alterung

KW - 6xxx Al-Legierung

KW - Wärmebehandlung

KW - TEM

KW - Korrosion

KW - Mikrostruktur

U2 - 10.34901/mul.pub.2023.275

DO - 10.34901/mul.pub.2023.275

M3 - Master's Thesis

ER -