Study of enhanced dry sliding wear behavior and mechanical properties of Cu-TiB2 composites fabricated by in situ casting process

摘要

In this work, TiB2 particulate reinforced copper matrix composites were fabricated by casting method, based on in situ precipitation reaction between B and Ti elements to form TiB2 particles in molten copper. The microstructures of the Cu-TiB2 composites were characterized using SEM and TEM. The results show that TiB2 particles are successfully formed in the copper matrix and the interfaces between these particles and the matrix are clean and well bonded. The friction and wear characteristics of the Cu-TiB2 composites were determined by carrying out dry sliding tests on pin-on-disk machine under varying loads, sliding speeds and sliding distances. A comparison between the volume wear losses of the composites under different conditions shows a significant improvement in wear property of the composites with respect to the pure copper. Furthermore, the mechanical properties of the composites with different TiB2 levels were also investigated. Both tensile strength and hardness are significantly improved with the increasing amount of TiB2 in copper matrix, while compromises of the elongation and electrical conductivity nevertheless occur in all cases.