Duktiteetti

Duktiteetti is a material property used in engineering and materials science to describe the extent to which a material can undergo plastic deformation before rupture. It is a measure of formability and is commonly discussed alongside strength and hardness. In many contexts, the term corresponds to the English concept of ductility.

Measurement and interpretation: In a standard tensile test, duktiteetti is most often quantified as percent elongation at fracture, the increase in gauge length expressed as a percentage. Reduction of area and true strain at fracture are also used, especially for comparing materials with different necking behaviors. High duktiteetti indicates the ability to undergo significant deformation before cracking, while low duktiteetti is associated with brittle failure.

Influencing factors: Duktiteetti depends on alloy composition, microstructure (such as grain size and phase distribution), temperature, and processing history (work hardening, annealing). Generally, there is a trade-off between strength and ductility, but processing and heat treatment can adjust ductility independently in many materials.

Material examples and applications: Copper and soft aluminum exhibit high duktiteetti, which makes them suitable for drawing into wires and forming into sheets. High-strength steels can show a wide range of ductility depending on alloying and heat treatment. Duktiteetti is a critical consideration in forming operations, safety analyses, automotive and aerospace design, and fatigue assessment.

History and terminology: The concept has long been a staple of materials science, with standardized methods for its assessment developed in the 19th and 20th centuries. In Finnish-language technical literature, duktiteetti is commonly used as the term for this property.

See also: ductility, tensile strength, formability, tensile test.