Low Temperature Sintering Of WC Based Diamond Enhanced Cemented Carbides With Novel Co-Free Binder Systems

In this work, Co-free WC based diamond enhanced cemented carbides (DECC) have been prepared and studied. Two approaches regarding the manufacturing process and metallic binder system were applied to minimize degradation of the metastable diamond into graphite. Two types of field assisted sintering techniques (FAST) were used, which allows consolidation of powders at lower temperatures within a much shorter dwell time compared to conventional sintering techniques. Binder systems were optimised to achieve a further decrease in sintering temperatures while maintaining a fully dense composite. Instead of Co, which is rated as toxic and a critical raw material, Fe, Ni and an in-situ formed alloy from Ni and Cu were used as metallic binder materials. These novel composites are compared to conventional Co-based DECC by means of microstructural and mechanical properties. SEM observations revealed that less diamond is degraded into graphite with the use of the studied novel binder systems.