Exploration of Various Forging Route Performance of Cast A356 Alloy Reinforced with Fly Ash and MWCNT Hybrid Composites

This proposed study is concerned with casted virgin A356 alloy and stir casted A356 reinforcement with 8 wt% power plant waste fly ash particles and 2 wt% of multi-wall carbon nanotube (MWCNT) hybrid composites further exposed by unidirectional (X), bi-directional (X and Y) and multi-directional forging technique (X, Y and Z). The micrograph and energy dispersive X-ray spectroscopy (EDS) study revealed that the stir-casted hybrid composites with multi-directional forging sample have even distribution of pour-free particles and fine grain refinement in the matrix. The increased hardness and tensile strength evidence the particle bridging inside the matrix as well as a load transfer strengthening mechanism as a result of fly ash and MWCNT representing thermodynamic reactions in the A356 melt. The multi-axial forged samples exhibited 35.21% higher hardness and 15.67% higher tensile strength of values of 96 VHN and 310 MPa over the cast virgin A356 alloy respectively. When compared to other samples, the stir cast hybrid composite with multidirectional forging has a tendency to have a lower wear rate and a higher friction coefficient. This was ascribed due to processing technique and constructive embedding with bonding ability of fly ash and MWCNT reinforcements over the A356 metal alloy. Also, the presence of MWCNT within the matrix clearly indicated good wet ability during sliding. The results exhibit superior resistance to abrasion and adhesive behaviour. Furthermore, the corrosion behaviour of the multi-axis forged hybrid composite samples was superior than any other samples which are evident through corrosion surface analysis using SEM. This outcome was prime consideration, especially in automobile applications. © 2022, The Institution of Engineers (India).