Synthesis, microstructure, and mechanical properties of in situ TiB2/Al-4.5Cu composites

In situ TiB2/Al- 4.5Cu composites with different TiB2 particle amounts were fabricated by the salt-metal reaction technique. The effects of in situ TiB2 on the microstructure and mechanical properties of Al-4.5Cu alloy were studied in this paper. The results showed that in situ TiB2 particles had significant effect on refining grain size and improving mechanical properties of as-cast Al-4.5Cu alloy. With the amounts of TiB2 particles increasing, the yield strength and ultimate tensile strength were improved, while the elongation reduced. The strengthening mechanisms of the in situ particle-reinforcing Al matrix composites were discussed, and the yield strength was predicted accurately by accounting for the three strengthening mechanisms and particle distribution.