Papers by Keyword: Aluminium Recycling

Abstract: This study proposes of harmonizing the original approach of aluminium alloy recycling through hot press forging. By eradicating the melting phase, most of the waste generation can be significantly reduced. To cope with the technology revolution, the finite element is utilised to predict the material behaviour without practically executing the trial. By employing three-dimensional finite element analysis through DEFORM 3D, the evaluations were demonstrated by simulating the isothermal forging process. The flow stress of the material was modified to adequate with the aluminium-based metal matrix composite used in the actual experiment. To that extent, this study found out that the strain of the workpiece had gradually increased on each step. A reduction of ~10% of the flesh observed in the simulation is roughly the same as existed on the experiment workpiece. Above all, the simulation conducted abides by the standard and follows the actual practice that has been done previously. Through the finite element utilization, this study discussed the performance of the recycled based composite. The result presented here may facilitate improvement in the recycling issue and also conserved the environment for the better future.

Abstract: In this research, mechanical properties of recycled 6061 aluminium alloy, produced by solid state recycling through extrusion, were compared to as-received billets. Aluminum 6061 chips were extruded using a hot extrusion machine. The effects of extrusion parameters on the mechanical properties of the produced recycled 6061 aluminium alloy were investigated. The objective of the study was to analyze the mechanical and structural features of the alloy after plastic consolidation. The extrusion processes were conducted at different preheat temperatures and preheat times, while the ram speed was kept constant. The findings of the study highlighted the potential of combining the extrusion process parameters as an efficient processing route for production of high quality and high-performance type of extruded billets. Tensile test results showed that, material extruded at 550°C exhibited better mechanical properties compared to that extruded at 400°C. The higher temperature resulted in a higher tensile strength being produced, at the expense of a trade-off in ductility. Overall, it was revealed that, the ultimate tensile strength (UTS) and elongation (ETF) of the produced recycled 6061 aluminium through extrusion exhibited mechanical and structural properties comparable to those of the as-received billets.

Abstract: The influence of the salt quantity on the recovery yield of aluminium scrap was studied considering an heterogeneous charge. The analysed heterogeneous charge was composed by different types of scrap such as turning, shredded materials and dross. The amount of salt was related to the scrap quality using the salt factor, which is defined as the ratio between the non-aluminium content in the scrap and the quantity of salt required. Two levels of salt factor were considered, 1.2 and 1.8. The analysis of variance was then implemented to verify the influence of the salt quantity on the recovery yield. The results were statistically confirmed using the Anderson-Darling test, the Dixon’s outliers test and the coefficient of variance. An increment of the recovery yield from 95% to 97% was revealed by increasing the salt factor from 1.2 to 1.8.

Abstract: Al7075 was recycled using the powder metallurgy technique to determine the effect of particle size distribution on the mechanical and microstructure of materials. Analysis of the microstructure, green density and microhardness was conducted to evaluate the performance of the recycled aluminium. The Al7075 was added with 4% of alumina and Al₂O₃ (3-4μm). The results showed that the green density of recycled Al7075 was lower than the pure Al7075. The average size distribution of the aluminium powder decreased with the increase in the ball mill time. As the temperature of sintering process increased, the green density decreased. The alloy’s microstructure sintered at 650°C has the lowest density, indicating a larger and more frequent porosity. The hardness of the samples with the addition of alumina was higher than the samples without the alumina. Sintering at 650°C also caused the hardness of the sample to increase in the range of approximately 50-62 Hv.

Abstract: The aluminium scrap market is undergoing rapid changes which will trigger off new recycling strategies. As the cast scrap market saturates it will become economically feasible to apply scrap also in aluminium wrought alloy production. As part of an EU project, Sustainable and efficient Production of Light weight solutions (SuPLight) a method for assessing life cycle environmental and economic consequences of applying aluminium scrap in high-end products has been developed. In this work, the method has been applied to assess life cycle environmental and economic impacts for six scenarios, embracing five various strategies for scrap treatment. This includes processes in material and component production, as well as fuel use during operation of vehicle and end-of-life treatment. The model for scrap strategies includes three grades of sorting and separation, plus simple refining by low-temp electrolysis and fluxing, and refining by Hoopes process. Not surprising, we find that sorting is beneficial compared to refining. More notable, perhaps, is the relative large difference between scenarios with regards to the environmental impacts considered. Finally, we discuss benefits from the life-cycle evaluation of scrap scenarios and use of the tool in business development.

Abstract: In the present study, the fabrication of an Al-based metal matrix composite material obtained directly from the melting of the aluminium used beverage cans in a modified rheocasting process is presented. The analysed operational condition is the shear rate applied to the bath and its influence on the properties of the obtained samples. Additionally, samples were heat treated at two different times. The characterization of the phases obtained in Al-based MMC was made by means of metallography, scanning electron microscopy with energy dispersive spectroscopy and electron microprobe with wavelength dispersion spectroscopy. The results show that some constituents were formed during the fabrication process of the MMC, mainly Al₆(Fe, Mn), which are partially transformed during the heat treatment. Additionally, samples were evaluated using dynamic mechanical analysis, and the results suggest that the obtained MMC could have very good mechanical properties, similar or superior to the aluminium alloys commonly used for structural applications such as 6XXX family.

Abstract: In early 2006, Fives Solios, namely Solios Thermal, was selected as a key cast house supplier by a major aluminium producer for a new 130,000te/yr re-melting facility. The project scope included not only the supply of modern melting and holding furnaces plus ancillary equipment, but also pre-heating furnaces, an air pollution control system, basic cast house engineering, cooling water schemes and complete turnkey project management. This project presented particular technical and logistical challenges and was required to meet exacting European environmental / efficiency standards for all major contractors involved. The facility was commissioned in March 2008 and the first production was on schedule. This paper will discuss the challenges that the Solios Thermal project team had to overcome, from layout of equipment to conclusion of the project; also how good communication and close collaboration between the customer and all major subcontractors resulted in a successfully implemented plant.

Abstract: Considering its advantage of low density and favorable insulation properties, there are several applications for lightweight autoclaved aerated concrete of uniform cellular structure.The raw materials for the manufacturing of cellular concrete are Portland cement, finely grounded sand and lime. These are batched and mixed with water and metallic aluminum powder finely divided. There is a reaction between the aluminum powder and hydroxides forming millions of hydrogen bubbles throughout the mixture.The aluminum powder is the highest cost component, and the objective of this work is replacing it for another gas forming agent, like recycled foil.The foils are grinded in a high energy ball mill (attritor). Quartz sand is mixed with aluminum foil to reduce the time required for grinding, obtaining spherical particles and ensuring a uniform distribution of aluminum in the gas forming agent.The activity of this gas forming agent was determined by the gas volumetric technique. Average particle size and compressive strength of the samples were measured. The relationship between volume of the gas released during the reaction and milling conditions are presented, showing its viability for producing a high quality cellular concrete.