Which term describes the ability to deform plastically under tensile load without fracturing?

• A. Crack lamination
• B. Exothermic
• C. Conductivity
• D. Ductility

Answer: (D)

Ductility is the property that describes the ability to deform plastically under tensile load without fracturing. A ductile material can be stretched or shaped permanently, showing noticeable plastic deformation before it breaks. In a tensile test, it will exhibit elongation and necking before failure, meaning it can absorb a lot of energy and undergo substantial deformation. This stands in contrast to brittle materials, which crack with little to no plastic deformation. The other terms don’t describe this behavior: exothermic refers to heat released in a reaction, conductivity to the ability to transfer heat or electricity, and crack lamination isn’t a standard term for material deformation.