Colorized SEM image of fractures in plasma spray-coated steel
Fracture toughness is the property of a material’s resistance to brittle fracture. Because the occurrence of flaws is impossible to avoid during processing of a material or component, fracture toughness is an important materials property. Materials with high fracture toughness will tend to undergo ductile fracture. Materials with low fracture toughness normally have brittle fracture.
Models can be used to calculate the fracture toughness and correlate to high load nanoindentation data. Typically these methods consider the flaw size and component geometry, and load condition. The fracture toughness is used to evaluate the ability of a component with pre-existing flaws to resist fracture.