The increase of B4C addition into an AA6061-B4C composite system will not be always an ideal choice for improved properties because of the issues related to incorporation, distribution, and interfacial wetting while stir-casting. In such a case, ultrasonication is considered to be an alternative to get the advantage of microstructural changes which in turn improve the properties. In the present study individual B₄C distribution and the refinement of microstructure was achieved at 4wt.%B4C. The improved specific ultimate and compressive strengths at 4wt.%B4C were observed as 36.32% and 43.92% whereas specific Vicker’s and Brinell hardness as 53.41% and 50.89% respectively.2009 Elsevier Ltd. All rights reserved.