Microstructural characteristics and mechanical behaviour of aluminium hybrid composites reinforced with groundnut shell ash and B4C

Abstract

In this study, aluminium hybrid composites were fabricated by reinforcing eco-friendly agrowaste, groundnut shell ash and boron carbide using squeeze casting method. Groundnut shell ash and boron carbide were added in ratios of 2.5:7.5, 5:5 and 7.5:2.5 percentages by weight. The impact on mechanical properties namely density, hardness, tensile strength, impact strength was studied, and the results were compared with the matrix alloy. The fracture mechanism of tensile and impact specimens were studied by scanning electron microscopy. Microstructural study reveals the uniform distribution and good bonding of reinforcements with clear interface in the hybrid composite. The hardness and tensile strength increased up to a maximum of 17% and 18.32%, respectively, and then slightly decreased while increasing groundnut shell ash particles. Increasing groundnut shell ash particles in hybrid composites decreases the impact strength and density to a maximum of 12% and 7.5%. Dimples, voids, cracks, clusters and particle fracture are characterised by fracture mechanism. Brittle fractures in the form of cracks, and particle fractures were formed due to the solid interfacial bonding between the reinforcements and alloy. Ductile fractures are the reason for high impact strength and are characterised by dimples and voids. The eco-friendly groundnut shell ash has the potential to serve as reinforcement for the development of composites.

Mechanical and tribological behaviours of aluminium hybrid composites reinforced by CDA-B4C

“…Here mass was calculated by using an electronic weighing machine and volume was calculate by multiplying the length and the cross sectional area of the specimens. From the calculated theoretical and experimental values the porosity of the fabricated samples were determined by (equation (3)) [35,36].…”

“…The benefits of adding agro waste are low cost, ease of access, low density and reduced pollution. Agro waste like ground nut shell ash (GSA) , bamboo leaf ash(BLA), rice husk ash (RHA), bagasse ash, palm kernel shell ash, maize stalk ash, corn cob ash (CCA), bean shell waste ash etc are researched and promising results have been reported [32][33][34][35][36][37][38][39][40][41][42][43][44]. Fatile OB et al have reported by adding the corn cob with SiC has no significant rise of porosity but while increasing the percentage of corn cob reduces the mechanical properties gradually.…”

“…CCA is suggested to be a promising low cost and high performing alternative hybrid material [31]. Venkatesh et al have studies the effects of reinforcing GSA and B 4 C particles through squeeze casting and reported that hardness and tensile properties have increased by 17% and 18% respectively and the increase in GSA particles has slightly reduced the impact energy [36]. Alaneme et al investigated the influence of BLA and reported that the ductility of the matrix has increased yet tensile strength has slightly reduced [40].…”

“…The elements present in CDA ash are SiO 2 , Al 2 O 3 , Fe 2 O 3 , MgO etc which could enhance the properties of aluminium. The benefits of adding CDA are low cost, ease of access, low density and reduced pollution [34][35][36][37][38][39][40][41]. Hence an attempt has been made in reinforcing CDA as second reinforcement in the matrix.…”

Experimental and theoretical analysis of tool life between plasma enhanced CVD and PVD multilayer nanocoated cutting tools

“…This gives high density and hardness to TiAlSiN PECVD coatings comparing PVDMNC coatings. The atoms molecules of TiAlSiN have a Si-N bond that gives high bonding strength [23,24].…”