<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Production and characterization<span style="mso-bidi-font-weight:bold"> of hybrid aluminum matrix composites reinforced with boron carbide (B₄C) and graphite</span></span>

Abstract

Aluminum matrix composites have been reinforced with Boron carbide (B₄C) and Graphite (Gr) for increasing mechanical properties and wear resistance. Additions of Boron carbide (B₄C) improves both strength and wear resistance of composites, but addition of B₄C alone in higher amounts makes the composite brittle and machining difficult. Thus, B₄C can be advantageously used as a reinforcement to overcome the problem of strength reduction in Gr reinforced composites, resulting in hybrid composites. Aluminum matrix composites reinforced with up to 12 wt % B₄C and 3 wt % Gr particulates are investigated in the present study. Hybrid composites exhibit better wear characteristics compared to aluminium alloy. Wear tests were carried out with loads varying from 10 to 40 N and sliding distances of 500 and 1000 m with a constant sliding speed of 1m per second. An interaction between load and sliding distance was observed in the composites which may be attributed to the presence of Gr particulates. Decrease in wear with an increase in speed and vice versa were observed with both load and sliding distance. Hardness of the composites measured using Vicker’s Hardness Tester indicated that hardness increased with increasing percent of B₄C reinforcement while addition of Gr imparted the lubrication effect in the composites.