Effects of TiC0.5N0.5 nanoparticles on the microstructure, mechanical and thermal properties of TiC0.5N0.5/Al-Cu nanocomposites

In this work, TiC0.5N0.5/Al-Cu nanocomposites with high mechanical and thermal performance were successfully synthesized via ultrasonic assisted casting route. The effects of TiC0.5N0.5 nanoparticle on the microstructure, mechanical and thermal properties of nanocomposites were systematically investigated from micro to nano scale. The microstructural analysis reveals that the TiCN nanoparticles in the matrix mainly exhibit two distribution patterns, i.e. intergranular and intragranular distribution. The experimental results show that the increased addition level can lead to the more refined and homogeneous microstructure and enhanced mechanical and thermal properties. The effects of ultrasonic treatment (UT) and NP addition on the microstructure evolution were discussed and it was found that the enhanced nucleation under ultrasonication and NP-induced growth restriction were the main reasons for the refinement of primary α-Al dendrite and Al2Cu phase. In addition, the 2 vol.% TiC0.5N0.5/Al-Cu nanocomposite can exhibit the optimum mechanical and thermal properties with its hardness, ultimate tensile strength, yield strength, elongation increased by 30 %, 26 %, 30 % and 46 % and coefficient of thermal expansion (CTE) decreased by 6.2 %, respectively as compared to the matrix alloy.