Influence of Ni content on the microstructure and mechanical properties of chromium carbide-nickel composites

In this study, chromium carbide-nickel composites were fabricated by mixing pure Cr3C2 and Ni powders at 1250, 1275, 1300 and 1325 degrees C for 1 h. The effects of the Ni content on the microstructures and mechanical properties of these composites were researched. Both Cr3C2 and Cr7C3 showed a well-defined crystallographic orientation. Two groups: (002)(Cr3C2)//(004)(Cr7C3) and [(2) over bar 10](Cr3C2) [(2) over bar 10](Cr7C3) were observed. The porosity of the specimens first declined and then risen slightly with an increase in the Ni content. The micro-hardness of the specimens showed an opposite trend. The bending strength and fracture toughness of the specimens first risen with an increase in the Ni content and then decreased, thus changing the fracture mechanism from inter-granular fracture to trans-granular fracture. The optimal temperature was 1300 degrees C and the composite with 20 wt% Ni showed the best mechanical properties.