In materials science and engineering, the ability of a material to undergo large deformation without fracturing or rupturing is referred to as ductility. Ductility is an important mechanical property of materials and is often desired in applications where the material needs to undergo extensive deformation without failure.


Ductile materials exhibit plastic deformation before failure. Plastic deformation occurs when the material is subjected to an applied load and undergoes a permanent change in shape without fracturing or rupturing. This is in contrast to brittle materials, which undergo little to no plastic deformation before failure.


Brittle materials, such as glass or ceramic, have very limited plastic deformation capabilities. They tend to fracture or rupture at relatively low strains or stresses without undergoing any significant plastic deformation. This makes them more prone to sudden failure under applied loads.


Elastic materials, on the other hand, exhibit reversible deformation. When an elastic material is subjected to an applied load, it deforms temporarily but returns to its original shape once the load is removed. These materials can undergo small deformations without permanent damage or failure.


Ductility is an important property in various engineering applications. For example, in the construction industry, materials used for structural purposes need to be ductile to withstand loads and deformations caused by earthquakes, wind, or other external forces. Ductile materials are also preferred in metal forming processes such as forging, rolling, or extrusion, where extensive plastic deformation is required.


In summary, the material in which large deformation is possible before absolute failure or rupture is termed as ductile. Ductile materials can undergo significant plastic deformation without fracturing or rupturing, making them desirable for various engineering applications.