Investigation on microstructural and mechanical properties of B4C-aluminum matrix composites prepared by microwave sintering

B4C reinforced aluminum composites were fabricated by microwave heating of the mixture of B4C (10, 15 and 20 wt%) and aluminum powders at 650, 750, 850 and 950 degrees C. The effect of different amounts of B4C on the microstructure and mechanical properties of aluminum matrix was examined. The maximum bending (238 +/- 10 MPa) and compressive strength (330 +/- 10 MPa) values were measured for composites sintered at 950 and 750 degrees C, respectively. The maximum hardness (112 Vickers) was measured for Al-20 wt% B4C composite sintered at 850 degrees C. XRD investigations showed the decomposition of boron carbide and also the formation of Al3BC by heating the composites at 850 degrees C. SEM micrographs showed uniform distribution of reinforcement particles in Al matrix. (C) 2015 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda. All rights reserved.