TY - BOOK

T1 - Design of new high-performance aluminium casting alloys

AU - Franke, Annegret Simone

N1 - embargoed until null

PY - 2006

Y1 - 2006

N2 - The focus of this thesis is in the design of high-performance aluminium casting alloys. The first section examines the design of new heat-resistant alloys for automotive cylinder head applications. The alloys were developed based on the AlMg3Si1 alloy system by the addition transition metals (Cr, Mn, Cu, Sc and Zr). In particular Sc and Zr result in outstanding mechanical properties at elevated temperatures up to 300°C when compared with AlMg3Si1 base alloy and AlSi7Mg0.3 standard cylinder head alloy. It was verified that the thermal stability of the AlMg3Si1+Sc,Zr alloy is based on coherent Al3(Sc,Zr) precipitates. The second part of this thesis examines the design of high-strength casting alloys for structural aerospace applications. This work was based on wrought alloys of the 2xxx (AlCuMg) and 7xxx (AlZnMgCu) series but involved the modification of the alloy composition. Generally, the feasibility to design high-strength casting alloys based on wrought alloys has been demonstrated. Overall, it was shown in the results that the AlZn8Mg8CuNiSi alloy is a more promising candidate than the AlCu4Mg4Mn alloy in terms of castability and hardness. However, it does not reach the excellent hot tear resistance and shrinkage sensitivity of the standard AlSi7Mg0.6 aerospace alloy. Therefore, further optimisation is required. In addition, also the potential of ultrasonic vibration and the optimisation of castings by bionic design have been evaluated.

AB - The focus of this thesis is in the design of high-performance aluminium casting alloys. The first section examines the design of new heat-resistant alloys for automotive cylinder head applications. The alloys were developed based on the AlMg3Si1 alloy system by the addition transition metals (Cr, Mn, Cu, Sc and Zr). In particular Sc and Zr result in outstanding mechanical properties at elevated temperatures up to 300°C when compared with AlMg3Si1 base alloy and AlSi7Mg0.3 standard cylinder head alloy. It was verified that the thermal stability of the AlMg3Si1+Sc,Zr alloy is based on coherent Al3(Sc,Zr) precipitates. The second part of this thesis examines the design of high-strength casting alloys for structural aerospace applications. This work was based on wrought alloys of the 2xxx (AlCuMg) and 7xxx (AlZnMgCu) series but involved the modification of the alloy composition. Generally, the feasibility to design high-strength casting alloys based on wrought alloys has been demonstrated. Overall, it was shown in the results that the AlZn8Mg8CuNiSi alloy is a more promising candidate than the AlCu4Mg4Mn alloy in terms of castability and hardness. However, it does not reach the excellent hot tear resistance and shrinkage sensitivity of the standard AlSi7Mg0.6 aerospace alloy. Therefore, further optimisation is required. In addition, also the potential of ultrasonic vibration and the optimisation of castings by bionic design have been evaluated.

KW - Aluminium Casting Alloy

KW - heat-resistant Alloy

KW - high-strength Microstructure Properties

KW - mechanical Properties

KW - thermomechanical Aging Castability Grain refinement Bionic

KW - Aluminiumgusslegierung

KW - warmfest Aluminiumgusslegierung

KW - hochfest Mikrostruktur Eigenschaften

KW - mechanische Eigenschaften

KW - thermomechanische Alterung Gießeigenschaften Kornfeinung Bionik

M3 - Doctoral Thesis

ER -