Effects of CeO2 additive on the microstructure and mechanical properties of in situ TiB2/Al composite

In this paper, CeO2 was investigated as an additive for in situ preparation of TiB2/Al composite using an exothermic reaction process via K2TiF6 and KBF4 salts. Experimental results indicated that when 0.5 wt.% CeO2 additive was added, the dispersion of TiB2 particles was improved significantly. Meanwhile, α-Al matrix grain was further refined. Compared with the composite without CeO2, the ultimate tensile strength, yield strength, elastic modulus and tensile elongation increased by 8%, 7%, 26% and 14%, respectively in as-cast condition, and the tensile fracture behavior of the composite with CeO2 belonged to a typical ductile fracture with microvoid coalescence.

Research highlights▶ The key problem in preparation of TiB2/Al composite is solved by adding CeO2. ▶ The reason of the segregation and settlement of TiB2 particles is analyzed. ▶ CP aluminum matrix grain is further refined by adding CeO2. ▶ Mechanical properties of TiB2/Al composite are further improved by adding CeO2.