The Microstructures of TiC–Ti₅Si₃-Reinforced Cu Matrix Composites Prepared by Ti–SiC Reaction

Abstract

In this work, the TiC and Ti5Si3-reinforced Cu matrix composites with different contents were successfully prepared through Ti–SiC reaction in Cu melts; accordingly, the microstructures of them were studied, and the hardness of the composites was tested. It is found that the synthesized TiC are granular, with a size ranging from 0.5 μm to 3 μm, while the Ti5Si3 are rod-like hexagonal prisms with a diameter of about 1 μm and a length-to-diameter ratio of about 5~25. In addition, it is noticed that many Ti5Si3 rods are actually Cu@Ti5Si3 core–shell structure rods. TiC and Ti5Si3 alternately distribute in the Cu matrix to form the hybrid reinforcement system. With the increase in Ti–SiC content, the TiC particles, Ti5Si3 rods and Cu@Ti5Si3 increased obviously, and the solid skeleton structure of TiC–Ti5Si3 was formed. The hardness of the composites was 2.2 to 2.74 times greater than that of the as-cast pure copper. It is deduced that, compared to the composites reinforced by either TiC or Ti5Si3, the formation of the TiC–Ti5Si3 hybrid system is more helpful for improving the properties of the composites due to the different morphologies of TiC and Ti5Si3.

Keywords

• Ti–SiC system
• reactive wetting
• hybrid reinforcement
• hardness