Development and tribological investigation of B4C reinforced AA5082 Aluminum alloy cast composites for automotive applications

Abstract

In this work, AA5082 alloy is used as base alloy to fabricate aluminum composites using fine reinforced particles of boron carbide (B4C). The conventional method of stir casting is employed for the production of composites. The particles are used with varying weight % of 5, 10, 15 and 20 for the composite fabrication. The microstructures of the composites are examined using the Scanning Electron Microscopy and x-ray Diffraction patterns. The hardness of the composites is tested and found to increase from 73 HV in base alloy to 93 HV in the AA5082 composite having B4C proportion of 15%. However, a slight decrease in hardness is also observed at higher wt% of B4C which could be due to agglomeration of particles. Evaluation of yield strength showed an escalation in the strong point with the addition of reinforced particles under the effect of orowan strengthening mechanism. Wear analysis conducted on Tribometer indicates that the escalation of load and sliding distance is proportional to the loss of material in composites whereas, wear declined with the rise of sliding speed. The micrograph examination of the wear tracks reveals the material removal mechanism from the composite as abrasive in nature. Pitting at certain places is also observed.