Synthesis and characterisation of B4C reinforced al6061 friction stir processed surface composites

Abstract

Current industrial trends show increased usage of lightweight high strength materials such as Aluminium, Titanium, Magnesium, etc., in their products and components. To achieve an improved service life, particulates reinforced metal matrix composites are being favored over the monolithic alloys. Researchers have reported undesirable defects and interfacial reactions while trying to fabricate such composites using conventional methodologies. This motivates the present work to use friction stir processing, an allied process of friction stir welding, to fabricate metal matrix composites. Structurally stable and most commonly used AA6061 alloy was taken for the experiment. B4C particles were used as reinforcements. Experiments were carried out using different process parameters like tool revolution and tool traverse speed or processing speed along with a constant axial force. The B4C particles were packed into a 1.5 mm groove on the Al6061 plate and friction processing was carried out. The SEM investigations on the composites showed a defect-free microstructure with a homogeneous distribution of reinforcement particles. It was found that the reinforcements increased the tensile strength of the composite by 50%. The hardness and wear-resistant properties of the composites had also improved considerably.