Thermomechanical Effects on Aluminum Matrix Composites Reinforced with AlB2 Particles

Aluminum matrix composites (AMCs) reinforced with aluminum diboride (AlB 2) particles are obtained through a casting process. A mixture design experiment combined with split-split plot experiment helped to assess the significance of the effects of cold work on precipitation hardening prior to aging. Both cold work and aging allowed higher microhardness of the composite matrix, which is further increased by higher levels of boron and copper. Microstructure analysis showed a good distribution of reinforcements and revealed a grain subdivision pattern due to cold work. Tensile tests helped corroborate the microhardness measurements. Fracture surface analysis showed a predominantly mixed brittle—ductile mode.