Fracture toughness studies in sintered SmCo5 magnets

•A strong anisotropy in the elastic modulus was observed in sintered SmCo5 magnet.•The hardness and fracture toughness did not show any prominent anisotropy.•Brittle cleavage fracture with (10 0) and (10 1) type cleavage planes observed.•Fracture toughness of SmCo5 magnets using Vickers indentation technique studied.•A suitable crack model and dimensionless coefficient value determined.

The fracture toughness of sintered SmCo5 magnets were systematically evaluated using both three point bend tests as well as Vickers indentation tests. These results were used for establishing the empirical dimensionless constant (χ) for evaluating indentation fracture toughness in SmCo5 magnets. The anisotropic behaviour of mechanical properties such as hardness, elastic modulus and fracture toughness was also investigated.