Duktiilitetin

Duktiilitetin refers to the tendency of a material to undergo significant plastic deformation before fracture when subjected to tensile stress. It is a key mechanical property that influences formability, toughness, and the mode of failure, and is especially important for materials used in forming processes and structural applications.

Ductility is commonly quantified by indicators such as elongation at fracture (percent elongation) and reduction of area after a tensile test. These values are obtained from standardized tests (for example ISO 6892-1 or ASTM E8) and may be complemented by measurements of true plastic strain or workability. Higher ductility means a material can sustain larger shapes of deformation before breaking.

Several factors affect ductility. Temperature generally increases ductility, while low temperatures can cause a ductile-to-brittle transition. Strain rate, alloy composition, microstructure, grain size, and the presence of second-phase particles also influence ductility by altering dislocation motion and crack initiation. Material processing, such as annealing or work hardening, can modify ductility by changing texture and grain structure.

Ductility is related to but distinct from malleability and toughness. Ductile materials absorb more energy before fracture and tend to neck rather than fail suddenly. There is often a trade-off between strength and ductility, and engineers tailor heat treatment and alloying to achieve a desirable balance for specific applications.

Common highly ductile metals include copper, aluminum, and many steels, which are widely used in wires, sheets, and forming operations. Materials like ceramics and many cast irons are typically brittle, with low ductility and limited deformability.