Metallographic investigation of tensile- and impact-tested aluminum composites

Abstract

The present work was performed on two composites: Al-15 vol.% B4C and experimental 6063/15% B4C. Additions of 0.45% Ti + 0.25% Zr were made to both composites melts. The composites were cast from the respective melts at 730℃ using two metallic molds to produce tensile as well as impact test samples. All samples were solution heat treated for 24 h at 540℃ for both composites, followed by aging at 200℃ for 10 h. Samples for microstructure and fractography were examined using field emission scanning electron microscopy. The results show that the powder injection technique used in this study produces composites with B4C uniformly distributed throughout the matrix. The strength and impact toughness of the two composites are controlled by the simultaneous precipitation of Al3Zr and Mg2Si phase particles depending on the matrix type. Hardening caused by precipitation of Mg2Si is more pronounced than that caused by Al3Zr phase precipitation. No B4C particle debonding was observed due to the presence of Zr-/Ti-rich layers surrounding the B4C particles. The cracks mainly propagate through the B4C reinforcement particles.

Optimizing the effect of reinforcement, particle size and aging on impact strength for Al 6061-red mud composite using Taguchi technique

“…This shows that the effect of particle size has been more significant than percentage reinforcement and aging time. When the aging time of the fabricated composite increased it gives a negative effect on impact strength [15]. This reduction in impact strength may be due to hardening of matrix because of aging.…”

“…are also used as reinforcement in AMCs. Reinforcement materials used may be of a single material or a combination of two or more materials [11][12][13][14][15]. There have been many fabrication methods for producing AMCs.…”