Difference Between Plasticity and elasticity

Plasticity vs elasticity
 

Elasticity and plasticity are two concepts discussed under material science as well as economics. Plasticity is a property of a material or a system that allows it to deform irreversibly. Elasticity is a property of a system or a material that allows it to deform reversibly. Both plasticity and elasticity play major roles in fields such as material science, engineering, economics, mathematical modeling and any other field involving designing and developing mechanical objects. In this article, we are going to discuss what plasticity and elasticity are, their applications, the definitions of plasticity and elasticity, the similarities and finally the difference between plasticity and elasticity.

Elasticity

Elasticity is a concept directly connected with the deformation of materials. When an exterior stress is applied to a solid body, the body tends to pull itself apart. This causes the distance between atoms in the lattice to increase. Each atom tries to pull its neighbor as close as possible. This causes a force trying to resist the deformation. This force is known as strain. If a graph of stress versus strain is plotted, the plot will be a linear one for some lower values of strain. This linear area is the zone which the object is deformed elastically. Elastic deformation is always reversible. It is calculated using Hooke’s law. The Hooke’s law states that for the elastic range of the material applied stress is equal to the product of the Young’s modulus and the strain of the material. The elastic deformation of a solid is a reversible process, when the applied stress is removed the solid returns to its original state. Elasticity is also discussed mathematical modeling to denote reversibly changeable boundaries.

Plasticity

Plasticity is a concept which is connected with the plastic deformation. When the plot of stress versus strain is linear, the system is said to be in the elastic state. However, when the stress is high the plot passes a small jump on the axes. This limit is when it becomes a plastic deformation. This limit is known as the yield strength of the material. Plastic deformation occurs mostly due to the sliding of two layers of the solid. This sliding process is not reversible. The plastic deformation is sometimes known as the irreversible deformation, but actually some modes of plastic deformation are reversible. After the yield strength jump, the stress versus strain plot becomes a smooth curve with a peak. The peak of this curve is known as the ultimate strength. After the ultimate strength, the material begins to “neck” making unevenness of the density over length. This makes very low density areas in the material making it easily breakable. Plastic deformation is used in metal hardening to pack the atoms thoroughly.