What Does Necking Mean?
Necking is a type of plastic deformation observed in ductile materials subjected to tensile stress. This deformation is characterized by a localized reduction in the cross-sectional area of the material, giving it a "V" or "neck" shape. During necking, a large amount of local strain is concentrated in a small region of the material; therefore, necking is often closely associated with yielding.
Corrosionpedia Explains Necking
Stress and strain are important concepts in materials engineering and can be related through a stress-strain curve or plot. The curve is obtained by observing and measuring the deformation in a material when a load is applied gradually to it. For ductile materials, the resulting curve shows three stages:
- A linear elastic region where the material undergoes elastic deformation (characterized by a linear graph).
- The strain hardening region that occurs when the specimen is subjected to the maximum stress it can sustain (also called the ultimate tensile strength or UTS).
- The necking region where the neck forms. At this point, the stress that the material can sustain decreases rapidly as it approaches fracture.