Mechanical Behaviour and Dry Sliding Wear Properties of Ceramic Boron Carbide Particulate Reinforced Al6061 Matrix Composites

An attempt has been made to evaluate the mechanical behaviour and wear properties of Al6061-9 wt% B4Cp composite prepared by stir casting. During the preparation of composites, K2TiF6 salt is used as flux to increase wettability of B4Cp at low temperature and also two step introduction of the mixture containing B4Cp and K2TiF6 flux (ratio of 0.3) is adopted to achieve better dispersion. Characterization of the prepared composites is done using XRD/SEM/EDS studies. Microstructural characterization has revealed fairly uniform dispersion of B4Cp in Al6061 matrix with clustering at few places. X-ray diffraction pattern taken on the prepared composite clearly reveals the presence of -Al, B4C, Ti compound layer (Al3Ti/TiB2), AlB2 and Al3BC. Mechanical properties of the prepared composites such as hardness, UTS and specific strength have been improved by 115.3%, 38.8% and 42.8% respectively in comparison with matrix alone. Further, fractography studies conducted on the tensile specimens revealed both ductile and brittle types of fracture in Al6061-B4Cp composites. Results of wear studies clearly suggest that addition of B4Cp into Al6061 matrix has reduced the wear rate by restricting dislocation pile up formed at the Al-B4Cp interface and also the formation of tribolayers between the contact surfaces reduces wear rate.