Toughening materials: enhancing resistance to fracture

It has been said that ‘God invented plasticity, but the Devil fracture!’ Both mechanisms represent two prime modes of structural failure, respectively, plastic collapse and rupture/breaking a component, concept developing materials with enhanced resistance to fracture can be difficult. This is because invariably involves compromise—between strength ductility, between toughness—fundamentally leading ‘conflict’ nano-/micro-structural damage toughening. Here, we examine major classes such toughening: (i) intrinsic toughening , which occurs ahead crack tip motivated by plasticity—this principal mode in ductile materials, (ii) extrinsic at, or wake of, associated crack-tip shielding—this generally sole brittle materials. We briefly how these distinct mechanistic processes have used toughen synthetic materials—intrinsically gradient multiple principal-element metallic alloys example glasses high-entropy alloys, extrinsically ceramics ceramic-matrix composites—in comparison Nature especially adept creating biological/natural are toughened one both classes, despite often consisting constituents meagre mechanical properties. The success driven its ability cultivate development length-scale hierarchical structures display ingenious gradients adaptability, philosophy need emulate more importantly learn synthesize make future unprecedented combinations article part discussion meeting issue ‘A cracking approach inventing new tough materials: stranger than friction’.