An investigation of microstructure and mechanical properties of aluminum matrix composite reinforced with b4c particulates manufactured by powder metallurgy method

Currently some composite materials, especially aluminum metal matrix composites with particulate reinforcement and related manufacturing methods are among important research topics because of their low density, high specific stiffness and specific strength, and, high wear resistance. Therefore, there exists a need for investigation of their mechanical properties and microstructures.In this study, microstructure and physic mechanical properties of Al-B4C composites, boron carbide (B4C) particulate reinforcements in 63-µm diameter aluminum matrix, sintered at 550 ºC, are studied. The effects of parameters such as reinforcement particulate size and reinforcement percentage on hardness, compression strength, and microstructure are investigated.Different sizes (22, 77, and 120-µm) and different amounts (3, 6, and 9 wt%) of B4C were added to the base material, and pressureless sintering was conducted at 550 ºC under argon atmosphere. Resulting microstructures, densities, and compression test behaviors are studied.It is observed that particle sizes and percentages of the reinforcement significantly influence the compression strength and hardness values. Visual inspection using SEM (Scanning Electron Microscope) analyses indicates that the microstructure of the composite is also greatly effected by these parameters. In addition, EDS (Energy Dispersive X-Ray Spectroscopy) and X-Ray Diffraction analyses were performed for reliable determination of the chemical composition.