TiB₂(-TiB)/Cu in-situ composites prepared by hot-press with the sintering temperature just beneath the melting point of copper

An improved hot-press method with the sintering temperature just beneath the melting point of copper was applied to prepare copper matrix composites. Cu-based hybrid composites reinforced with most TiB₂ particles and a small amount of TiB whisker have been in-situ synthesized from the primary Cu, Ti (or TiH₂) and B powder mixtures. The reinforcement in TiB₂(-TiB)/Cu composites often appears as bubble-like cluster, which is believed to result from the local melting of Cu-Ti intermetallic compound forming in pre-sintering stage. Subsequently, the formation mechanism of the reinforcement was identified as the in-situ reaction occurring at the original site of Ti (or TiH₂) by diffusing B from Cu matrix into Cu-Ti liquids. As compared with Cu-Ti-B system, the composites fabricated from Cu-TiH₂-B powder mixture have more favorable microstructures and thus better overall performance.