Fabrication And Multi-Response Optimization Of Process Parameters Of Aluminium Metal Matrix Composite And Its Machinability

Abstract

Aluminium Metal Matrix Composites are potential materials for aerospace and automobile industrial applications due to its enhanced mechanical and tribological properties. Aluminium reinforced with Silicon Carbide particles have been developed with enhanced mechanical and tribological behavior but, it lacks wettability between matrix and reinforcement and cause weak bonding which reduce the degree of enhancement. The objectives of this study were to fabricate Aluminium based metal matrix composite with enhanced wettability at varying stirring speed (350, 450, 550rpm), stirring time (5, 10, 15min), wt. % of SiC (0, 5, 10 wt.%), and wt.% of MoS2 (0, 2, 4 wt.%). Nine samples were fabricated using stir casting based on Taguchi L9 orthogonal array. Hardness, tensile strength, tensile toughness and wear resistance of developed composite were investigated and analyzed as a single response characteristics using Taguchi’s S/N ratio and as multi response characteristic using Hybrid Taguchi Grey Relational Analysis (HTGRA). Results revealed that, addition of SiC in composite showed better hardness, tensile strength, tensile toughness and wear resistance. Addition of MoS2 in composite showed better hardness, tensile strength and tensile toughness only upto 2 wt.% of MoS2 and in case of wear rate addition of MoS2 in composite up to 4% showed better wear resistance. Al-SiC-MoS2 hybrid composite shows better enhancements in hardness, tensile strength, toughness and wear resistance than Al-SiC composite. Therefore, the enhancement of wettability has been achieved due to the addition of MoS2 in Al-SiC composite. From HTGRA, the optimum condition for multi-response characteristics has been obtained at A3B2C3D2. The machinability of the optimum composite also studied at varying spindle speed (500, 750, 1000rpm), feed rate (0.1, 0.2, 0.3mm/rev) and depth of cut (0.2, 0.3, 0.4mm) on CNC lathe using tungsten carbide tool. Surface roughness and material removal rate of machined composite were measured and analyzed as single response characteristics using Taguchi’s S/N ratio and as multi-response characteristic using Hybrid Taguchi Grey Relational Analysis (HTGRA). The results revealed that, Surface roughness decreases with increasing the spindle speed and increased with increasing feed rate and depth of cut. Material removal rate increases with increasing feed rate, depth of cut and spindle speed increases. Feed rate is the highly influential parameter which influences the surface roughness and MRR in machining of hybrid composites. From HTGRA, the optimum prediction condition for multi-response characteristics has been obtained at N1f3d3.