Plastic flow (/ˈplæstɪk floʊ/) refers to the continuous deformation of a solid material under stress, without any noticeable change in its elasticity. The term 'plastic' here refers to the permanent nature of the deformation, which is why the term 'plastic' also applies to synthetic materials made from polymers, such as plastic bags or containers. The IPA phonetic transcription clearly shows the pronunciation of each syllable in the word 'plastic flow', which is essential to understanding the correct spelling of this technical term used in materials science and mechanical engineering.
Plastic flow refers to the phenomenon or process by which a material, typically a solid, deforms or changes its shape due to the application of stress or external force. Unlike elastic deformation, where a material returns to its original shape once the stress is removed, plastic flow results in a permanent, non-reversible change in shape.
When stress is applied to a material beyond its elastic limit, the atoms or molecules within the material start to move and reorganize themselves, resulting in the material's ability to undergo plastic flow. This reorganization involves the sliding, shearing, or rearranging of the material's internal structure, allowing it to maintain the new deformed shape even after the stress is released. This behavior is observed in materials like metals, polymers, rocks, and certain ceramics.
The underlying mechanism behind plastic flow is often attributed to the movement of dislocations within the material. Dislocations are defects or irregularities in the crystal lattice structure of a material that can glide or move, allowing for the deformation to take place. As more stress is applied, more dislocations become active, enhancing the material's plasticity.
The concept of plastic flow finds applications in various fields, including engineering, material science, geology, and manufacturing. Understanding the behavior of plastic flow helps engineers and scientists predict and control the deformation of materials, enabling the design and production of durable and reliable products.
The word "plastic flow" is derived from the adjective "plastic" and the noun "flow".
The term "plastic" originates from the Greek word "plastikos", meaning "capable of being shaped or molded". It was first used in reference to materials that can be easily molded or deformed without breaking. Eventually, "plastic" came to be associated with the ability of materials to undergo permanent deformation under stress.
The word "flow" comes from the Old English word "flowan", meaning "to move along smoothly and continuously". It refers to the act of a substance moving or being displaced in a continuous manner.
When combined, "plastic flow" refers to the deformation of materials in a manner that is permanent yet smooth and continuous, without fracturing or breaking. This term is commonly used in various scientific and engineering disciplines, especially in the context of materials science and mechanical engineering.