Abstract
This research introduces an integrated direct technique for recycling aluminium wastes or scraps instead of conventional method which it will be carried out without melting phase. This technique is characterized by fewer steps and gives benefit on low energy consumption and operating cost. In this paper, it will focus on the powder metallurgy process and Aluminium Alloy 7075 (AA7075). It reveals the performance of recycled aluminium chips on their mechanical properties and surface integrity (microstructure) by comparing them with the original aluminium one. In this research also, it is expected to reveal the possibility of this recycled aluminium chips to be used as a secondary resources as an alternative to overcome the shortage of primary resources. Analysis of the microstructure, density and microhardness were conducted to evaluate the performance of recycled AA7075. The AA7075 was added with alumina and graphite. The microstructure analysis was carried out using field emission scanning electron microscopy (FESEM), while mechanical properties have been study using Electronic Densimeter and Micro Vicker Hardness Tester. The results show that the density of recycled Al7075 is varies between with and without addition of alumina and graphite. As the temperature of sintering process increases, the density increased. The alloy’s microstructure sintered at 650oC has the highest density which shows dense compare to sample with no addition that shows porosity. The microhardness of the samples with the addition of graphite are higher than the samples with and without alumina that range from 61.7 to 71.0 Hv.
