Effects of TiB2 content on microstructural evolution, microhardness and tribological behaviours of Al matrix composites reinforced with TiB2 particles.

In this study, Al2024/TiB 2 composites with different TiB 2 fractions (5, 10 and 15 vol%) were fabricated by high-energy ball milling and spark plasma sintering. The effects of TiB 2 fraction on the microstructure, hardness and wear resistance of the composites were explored to determine the optimal TiB 2 content in the composite with optimal properties. An increase in Vickers hardness of the composites correlates with the increased TiB 2 content, and the Al2024-15TiB 2 composite exhibits the highest hardness. The wear rate of the composite initially increases and then decreases with higher TiB 2 content. Notably, the Al2024-10TiB 2 composite demonstrates the best wear resistance with a wear rate of 1.14 × 10−4 mm³/Nm, representing a 96.81 % reduction compared to the unreinforced Al2024. The deteriorated wear resistance of the Al2024-15TiB 2 composite was attributed to the decreased toughness and severe three-body abrasion caused by the excessive TiB 2 particles. [ABSTRACT FROM AUTHOR]