Mechanical Properties of Cr3B4 Cermets Cemented by Different Metallic Binders

Ezzat S. Elshazly, A. A. M. Abdelrahman, M. A. A. Elmasry
2012 International Journal of Materials Engineering  
Cr 3 B 4 cermets cemented by cobalt and iron as a metallic b inder up to 20 wt% were prepared by hot pressing at 1500 and 1800℃ under a pressure of 14 and 41 MPa for 1hr. The binder addition enhanced the densification of Cr 3 B 4 cermets due to the formation of liquid metal and its flow into the pores. It is also found that the temperature and pressure have a pronounced effect on densificat ion. The densification of Cr 3 B 4 is enhanced by the addition of cobalt and iron due to the liquid phase
more » ... to the liquid phase format ion, therefore, the hardness and fracture toughness were improved, to a certain extent. A composite with a both high Vickers hardness of 35.98 GPa and a modest fracture toughness of 2.5 MPa.m 1/2 could be obtained by the addition of 8 wt% cobalt at 1500 o C and 14 MPa. There is an overgrowth of the boride grains which surly reduces the hardness but has less impact on the fracture toughness.
doi:10.5923/j.ijme.20120204.05 fatcat:u6dtwnpqjnfpxc5x7q5xxpddc4