Published online by Cambridge University Press: 01 January 1992
The fracture toughness at room temperature of a brittle nickel silicide containing the ductile phases Ni(Si) and Ni3Si has been investigated. The microstructure was comprised of a brittle nickel silicide matrix, ductile Ni(Si) particles distributed within the matrix, and Ni3Si rims around the particles. It was obtained by annealing hot-extruded Ni-23 at.%Si (with and without 0.19 at.% boron) at 1100°C and then air cooling. The fracture toughness values were in the range of 13 MPa m1/2 to 22 MPa m1/2. Systematic effects of annealing time and of boron were not apparent. It would appear that the incorporation of the ductile particles has a beneficial effect on the fracture toughness of an otherwise brittle silicide.