Multi-Objective Optimization of Hybrid Aluminum–Composite Tube Under Axial Crushing

Since lightweight and energy-absorbing materials have an effective role in occupant safety during accidents, the use of hybrid aluminum–composite tubes and their optimum designs are of great importance in the crashworthiness. In this study, finite element simulation and multi-objective optimization of a hybrid aluminum–composite tube are performed under axial crushing to investigate the effect of metal volume fraction (MVF) on the objective functions, the specific energy absorption and the peak force. Besides, the effects of annealing and tempering of ductile aluminum alloys (Al-6061) as the base metal of hybrid tubes are investigated. The optimum values of the objective functions are obtained at [Formula: see text] (the same thickness of aluminum and composite). Also, annealing of ductile aluminum alloys has a negative effect on the objective functions. As a guideline for the design of fiber metal laminates under crushing, it is suggested to use tempered Al-6061 and increase the thickness of composite material so that [Formula: see text].

Transient Liquid Phase Bonding of Aluminum Using Aluminum Base Interlayer under Argon Flux

An aluminum base interlayer was used for transient liquid phase bonding of pure aluminum under argon flux. The bonding was carried out at 595°C for 2 minutes under 7MPa. Microstructure of the joint was studied with SEM and EDX, and the mechanical properties were analyzed by tensile test and bending test. A homogenous bonding zone is observed in the joint. The defects in the joint are silicon oxides and voids. The tensile strength of the joint is 190MPa, and no failure occurs when the joint is bent to 180°. This indicates that TLP bonding can produce a strong and ductile Aluminum joint, which is equivalent to the base metal.

The Effects of Thickness on the Formability of 2000 and 7000 Series High Strength Aluminum Alloys

This paper studies the effects of sheet thickness on the forming limits of high strength aluminum alloys commonly used in the aircraft industry. The selected materials are 2024-T3 and 7075-T6 representing 2000 and 7000 series aluminum alloys. Two sets of experiments are carried out to identify the effects of sheet thickness on the forming behavior of the selected alloys. The first set of the experiments is tensile testing. The tensile properties of sheets with different thickness and different materials including the plasticity parameters are determined in the first set of experiments. The second set of the experiments is air bending. The minimum bending radius of the different series of materials is determined in the second set of experiments. The results of the tensile testing and air bending are studied both separately and in comparison with each other to identify the trends and to understand the mechanisms governing the observed trends. It is shown that the behavior of the studied alloys is to some extent different from the behavior of more ductile aluminum alloys and mild steels.