Studies on the characterization and mechanical behaviour of the recycled aluminium scraps modified with manganese addition
The experimental works have been carried out to enhance the properties of recycled aluminium scraps by the addition of manganese. The following are the main hypothesis: 1. Despite numerous works claiming to use manganese in aluminium scraps, none of the experimental works have carried research on scraps and the experiments were carried out on alloys by addition of the impurities. 2. The dissolution of manganese in aluminium is very low but the published works claim higher dissolution of manganese even when added in the form of powders 3. Experimental works have been limited to the 1, 2 and 5 kg furnaces and the experimental works are not projected to higher loads and thus irrelevant for real-time applications in the industry. The present work focuses on recycling aluminium troma scraps and enhancing the qualities of recycled aluminium troma scraps by adding manganese to the scrap melts. This work is carried out to extend the works carried out by (Zhijun Zhang, 2013) on recycled aluminium alloys. Most research trials have been directly conducted on aluminium scraps with the exception of the works of Puga et al. (2009), who carried out research works on recycling aluminium swarfs and Xiao et al. (2012) who investigated the recycling of distributed turning scraps.
Steps to reproduce
The scraps should be carefully selected and sorted, namely, the troma scraps that are the alloy wheel scraps from automobiles should be chosen. Initially, 30 kgs of scrap should be weighed and added to the crucible made of Silicon Carbide (SiC) placed in an Electrical Resistance furnace. The scraps should be melted at temperatures of 750±10°Celsius and poured at a temperature of 680±10°Celsius into dies that were preheated. Chemical compositions should be analysed using Optical Emission Spectroscopy. Then the manganese powder which is 99% pure is procured and ball-milled using a High energy ball miller at the speed of 250 RPM. The size of the ball-milled Mn powder should be analysed using the zeta sizer. The ball-milled powder should be added to the molten recycled aluminium scraps after being weighed in ratios of 0.25, 0.5, 0.75 & 1% of the molten aluminium individually. The melt should be poured at a temperature of 680±10°Celsius into dies that were preheated. Machining of the samples should be done carefully to ensure the surface is proper for the analysis of chemical compositions. The samples have to be cut to dimensions of 2 x 2 mm to be analysed through the X-Ray diffractometer to understand the phases present in the material. The tensile tests were performed according to ASTM-E8 Standards and the mode of fracture was analysed using FESEM techniques. The morphology of the samples was also analysed using the FESEM techniques to understand the modifications to the recycled aluminium scraps by the addition of Manganese powders. Sliding wear behaviour was analysed using the Pin-on-Disc apparatus and the influence of Mn on the wear behaviour was analyzed. The corrosion analysis was done by placing the aluminium samples in the Salt-spray chamber for a period of 240 hours. The tafle plot was done to analyse the corrosion in the samples.