Investigating the effect of non-uniform ceramic dispersion on the mechanical properties of hybrid Al-Cu composite via powder metallurgy route

Abstract

This study has used the powder metallurgy route to investigate the influence of varying ratios of SiO₂ and CrB₂ reinforcement on the mechanical properties of aluminium-copper alloy. Aluminium-copper alloys have been used in the fabrication of aircraft and automobile components. In the present work, SiO₂ has been synthesized by a sol-gel process, and UV-Vis and FTIR analyses have confirmed the quality of the synthesis. Varying ratios (0:1, 0.5:1, 1:1) of CrB₂ and SiO₂ have been mixed with Al+4wt% Cu, and the mixture undergoes cold compaction and sintering. The mechanical properties of the base metal alloy and hybrid composites have been compared. A maximum sintered density of 92.1% has been observed after reinforcement. Hardness values have consistently increased with increasing reinforcement amount. Adding 5 wt% of CrB₂ and SiO₂ has increased hardness by 52%, whereas compression strength has decreased by 34.4%. As the ceramic percentage has increased, compression strength has decreased, contrary to the reported trend. In homogeneously dispersed ceramic particles on a metal matrix and poor interfacial bonding have been attributed to this reduction. The results have inferred that the homogeneity of reinforcement distribution serves as a decisive factor in determining the ultimate mechanical properties of composites fabricated via powder metallurgy