Production and Properties of Novel Crb2 Reinforced Copper Matrix Composites by In Situ Processing

Abstract

Copper matrix composites reinforced with CrB₂ have been produced by in situ processing. The introduction of surface-active cadmium and rare-earth metals were employed to improve the composite structure and, as a consequence, mechanical characteristics. Pure copper, chromium, and boron as starting materials were used in this study. In contrast to previous approaches to copper matrix composites production, ours relies on the introduction of starting components to a pre-deoxidized melt under a layer of finely ground graphite. The challenges associated with grain milling and columnar structure reduction, using the surface-active and microalloying additives are explored. It was found that the introduction of cadmium and rare-earth metals leads to both milling of the copper grain and composite hardening. The mechanical properties of the composites were investigated. The composite hardness significantly increased with increasing CrB₂. Composites that match the complex criteria of the International Annealed Copper Standard were obtained.