Effects of boron addition on the microstructure and properties of in situ synthesis TiC reinforced CuTiC composites

In situ TiC particles reinforced Cu matrix composites have been prepared by melt reaction method in this work. It is found that, during the preparation, not all the added graphite can react with soluble Ti to form TiC due to its poor wetting and very limited solubility in Cu melt, which will lead to residue of both graphite and Ti in the composites. Because the residual Ti will dissolve in the Cu matrix, it will seriously degrade the conductivity of the composites. In order to improve the electrical conductivity of CuTiC composites prepared by the melt reaction method, boron can be added to the composites to consume the residual Ti by the formation of TiB2. It is confirmed that the addition of B will make the distribution of the reinforced particles more homogeneous, most of all, can remarkably improve both the hardness and electrical conductivity of the CuTiC composites.