Transforming waste red mud and fly ash to wealth by designing a hybrid Al alloy composite with improved mechanical and tribological properties Umwandlung von Rotschlamm und Flugasche in Wohlstand durch Entwicklung eines hybriden Al-Legierungsverbundwerkstoffes mit verbesserten mechanischen und tribologischen Eigenschaften

In the present work, we demonstrate the development of a cost-effective hybrid composite of aluminium 6063 alloys by utilizing some industrial wastes like fly ash and red mud as reinforcement. Alloy composites have been produced with varying concentrations of reinforcement by a two-step stir-casting method. X-ray diffraction (XRD) confirmed the presence of fly ash and red mud whereas microstructural analysis through optical microscopy showed a uniform distribution of the reinforcements within the alloy matrix. The composite formed with optimized weight fractions of red mud and fly ash exhibited higher ultimate tensile strength in comparison with base aluminium alloy. Furthermore, the dry sliding wear behaviour of the alloy and its composites have been investigated at low sliding speed against a hardened disk at three different loads (2 kg, 3 kg and 4 kg). The wear rate increases with increasing load in the alloy as well as in the composite. Sem images of worn surfaces of the hybrid composite exhibit fewer grooves when 5 wt.-% of both reinforcements are present. Essentially, the overall wear rate of the composite is found lower than the base alloy. Hybrid composites with 5 wt.-% of both reinforcements show maximum wear resistance.