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Ductility

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We know by the name of ductility the ability of a material to permanently deform , for example, stretch, bend or extend as a response to stress . The most common steels, for example, are quite ductile and can therefore accommodate local stress concentrations . Brittle materials, such as glass, cannot accept stress concentrations because they lack ductility and therefore break very easily. When a sample of material is subjected to tension , to the first is deformed so elasticabove a certain strain , called the elastic limit, and the strain becomes permanent.

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What is ductility?

It is the property that some materials have that when they are under the force or the effect of an action, they can deform as a material but without having to break .

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  • What does it consist of
  • Ductility properties
  • As measured
  • Importance
  • How it differs from malleability
  • Ductility of metals
  • Other examples

What does it consist of

Ductility consists of the ability of a certain material to be stretched or deformed without causing a fracture . For this reason, it is a characteristic that tells us how “soft” or how malleable a given material can be. The ductility of steels varies according to the types and levels of alloying elements present. The ductility value of a material can be described as the ability of the material to undergo plastic deformation and at the same time to resist the load.that has been applied. The more ductile a material is, then it is said to have a greater ability to deform under the load that has been applied.

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Ductility properties

It has an important property known as plasticity . This property refers to the ability of a certain body to deform without having to break .

As measured

The value of the ductility that a material has can be described as the ability of the material to undergo plastic deformation and at the same time to resist the load that has been applied. The more ductile a material is, then it is said to have a greater capacity for deformation under the load that has been applied. The ductility of a certain material can be measured by means of a test piece that is placed in a traction machine and is defined as the percentage of elongation.that can support a material when it reaches the plastic zone before it breaks completely. Many experts also state that there is no test that is specific about ductility, but that the tensile test is still the most suitable for obtaining data on the term.

It can also be used the test resistance to bending , which is possible to obtain a series of data regarding ductility material having depending bending of and strain . Although there are no standard terms that allow us to present exact results, some terms that are associated with bending tests on materials can be applied.

Ductility can be specified as a percentage of elongation before rupture as:

DL = 100% (Lf – L0) / L0 (1)

Where

  • DL = ductility related to elongation
  • Lf = final length of specimen at fracture
  • L0 = original length of the specimen

Alternatively, the ductility can be specified as a percentage reduction of the area as

DA = 100% (A0 – Af) / A0 (2)

Where

  • DA = ductility related to the reduction of the area
  • Af = final area of ​​the sample at the fracture
  • A0 = original area of ​​the specimen

Importance

With some materials have characteristics and ductility properties, it is possible to meet certain needs for example, it enables conduction of electricity , in addition to materials that are very important for large constructions of INGIENERIA . Ductility can even be used in earthquake resistant designs due to its high elastic capacity.

How it differs from malleability

We know by malleability the property of matter, which together with ductility makes it possible for bodies to be worked through deformation . Ductility is a process that relates to the obtaining of wires instead the malleability allows obtaining thin sheets of material without tearing it. Ductility is the property of some metals and alloys that when under the action of a force can deform without breaking, allowing wires or threads to be obtained. The metals that present this property are known by the name ofductile .

Ductility of metals

  • Iron : it is a metal with magnetic properties and a lot of hardness and density, so when it is in its pure state it is not very useful, but by alloying it with carbon it is possible to obtain steels , which according to the proportion of this element present may be more or less ductile and more or less resistant.
  • Steel : it is a mixture of iron and carbon that forms a hard and relatively ductile material , especially combined with boron to form highly ductile surface hardness wires , or in corrugated steel used in the construction sector .
  • Zinc : in its pure state it has high ductility and malleability , so it can be rolled into sheets , tensioned and deformed , although it is very fragile . It is widely used in alloys such as that produced by brass .
  • Lead : it is a heavy , grayish, flexible metal that melts easily . It is used today as a cable cover , since its unique ductility makes it extremely appropriate, as it can be stretched to suit the needs to be covered.

Other examples

Other examples of materials that have ductility are the following:

  • Plasticine – extremely ductile material made from calcium , petroleum jelly, and some aliphatic compounds .
  • Platinum : very ductile and used in jewelry and laboratories , it is also resistant to corrosion.
  • Aluminum : widely used in industry of materials , but its ductility is not extreme, corrosion resistant and tension.

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