What is the term for the ability of a material to deform easily under tensile force or to sustain plastic deformation before rupture?

• A. Hardness
• B. Elasticity
• C. Ductility
• D. Conductivity

Answer: (C)

Ductility is the property described. It refers to a material’s ability to undergo significant plastic deformation under tensile loading before it ruptures. In practical terms, a ductile metal can be stretched or drawn out and will nose and neck while continuing to deform rather than snapping instantly. This behavior is typically measured in a tensile test by looking at how much the material elongates before fracture or how much its cross-section reduces.

Ductility contrasts with elasticity, which is about reversible, non-permanent deformation when the load is removed, and with hardness, which is about resistance to indentation. Conductivity is unrelated to mechanical deformation, as it concerns how well a material conducts electricity or heat. Materials like copper, aluminum, and many steels are highly ductile, enabling forming and shaping processes, while ceramics tend to be brittle with low ductility.