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The continuous annealing treatment of 5052 aluminum alloy pipe fittings for alpine skiing sticks was carried out in the temperature range of 300-500 °C by means of metallographic observation and mechanical property test. The results show that with the increase of annealing temperature, the strength and hardness of the samples decrease continuously, and the impact value, section shrinkage and elongation change significantly. The experimental results provide a technical reference for preventing the fracture of alpine skiing sticks during use. [ABSTRACT FROM AUTHOR]

The continuous annealing treatment of 5052 aluminum alloy pipe fittings for alpine skiing sticks was carried out in the temperature range of 300-500 °C by means of metallographic observation and mechanical property test. The results show that with the increase of annealing temperature, the strength and hardness of the samples decrease continuously, and the impact value, section shrinkage and elongation change significantly. The experimental results provide a technical reference for preventing the fracture of alpine skiing sticks during use.

Electromagnetic impaction forming of 5052 aluminium alloy sheets using a V-shaped die and a conical die was performed. The conventional quasi-static forming limit curve (QS-FLC) is obtained according to the linear loading condition, which can only describe linear strain paths. However, it cannot accurately evaluate the formability of electromagnetic impaction forming, especially strain paths that have become highly non-linear. In this study, the formability of electromagnetic impaction forming, which considers a bilinear strain path and a continuous highly non-linear strain path, was investigated. The conventional QS-FLC is no longer suitable to evaluate the formability of electromagnetic impaction forming. Therefore, modified FLCs were established in strain space that follow bilinear strain paths and continuous non-linear strain paths. The actual formability improvement was compared with the modified FLC. The maximum safe strain of bilinear strain paths near the sidewall of V-shaped specimens increased in formability by approximately 30% at the discharge voltage of 20 kV compared with conventional QS forming. The maximum safe strains near the apex of the conical specimens increased in formability by approximately 100% at the same discharge energy. It should be noted that the increase in formability above the modified FLC is a conservative estimate, because the limit strains at the necking location were not known in the electromagnetic impaction forming. The influencing factors of the formability improvement of 5052 aluminium alloy sheet in electromagnetic impaction forming were also discussed. [ABSTRACT FROM AUTHOR]

It was found that both laser welding and laser-metal inert gas (MIG) hybrid welding with a fibre laser could be applied to join 5052 aluminium alloy plates successfully; however, the quality of welds from two processes can be quite different. To understand the impacts of the welding processes on the quality of welds, a comparative study was conducted to look into how a welding process can be selected to meet the expected quality of welds. The quality of welds was measured by weld appearance, microstructure and mechanical properties. The reported work has shown the quality difference of welds at the following aspects: (i) on the appearance of welds, the laser-MIG hybrid welding process led to fully reinforced welds, and the laser welding process resulted in uniformly underfilled welds with root sagging; (ii) On the porosity, the welds from the laser-MIG hybrid welding process was larger than that of the laser welding process; (iii) On bead microstructure, the welds from the laser- MIG hybrid welding process were equiaxed dendritic, and the grain sizes in the fusion zone (FZ) were coarser than that from laser welding process; (iv) On the distribution of microhardness, the microhardness at the heat affected zone (HAZ) was lower than that at the FZ and the base metal (BM) in the laser welding process, while the microhardness at the FZ was higher than that in BM; and (v) Finally, the tensile strengths of welds from laser welding process and the laser-MIG hybrid welding process were 174 and 114 MPa, respectively. The tensile strength of welds from the laser welding process was up to 71.71% of that of the substrate. [ABSTRACT FROM AUTHOR]

Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains’ dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld; at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal.

In this paper the effect of immersion duration on mechanical properties of cyrolled and non-cryorolled A5052 aluminium sheet alloy were studied. The sheets with and without annealing were rolled up to 30% reduction at liquid nitrogen temperature. The mechanical behaviour of the sample were evaluated through hardness and tensile tests performed at room temperature. The evolution of microstructure was investigated using optical microscopy (OM). The optimum immersion duration of A5052 Al sheet alloy was 60 minutes as the hardness, tensile and yield strength were the highest for annealed sample with and without directly cryorolled. All the cryorolled samples showed elongated grain. [ABSTRACT FROM AUTHOR]

Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains' dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld; at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal. [ABSTRACT FROM AUTHOR]