To understand this topic, we strongly recommend you to read about what is stress-strain charts of materials and what kinds of informations can we obtain about materials from these charts. In this article, the material types are axplained according to their stress-strain characteristics that they are showing in their stress-strain charts.
We can read materials properties from their stress-strain charts’ characteristics. Brittleness, plasticity, elasticity of materials can be interpreted from their stress-strain charts. These types are; Perfecty elastic, elastic and perfectly plastic and elastic and strain hardening materials.
If you take a look at the first curve above, this stress-strain curve has only a elastic region. So this type of material is called as perfect elastic. There is no exact plastic region of this material. Which means that, material breaks up after a elastic strain value. The example of these kinds of materials can be; ceramic materials. Ceramic materials are generally very brittle materials that if you apply a stress to these materials, after a certain point, they will break out without plastically deforming.
The second curve shows about elastic and perfectly plastic behaviour. When a stress applied to these materials, there is an elastic deformation up to yield point. With the same stress level at yield point, material is going on with plastic deformation. This kind of material behaviour is shown by lead at room temperature, also at high temperatures, metals show this kind of behavior.
Most ductile metals show the behaviour as in third stress-strain characteristics. Up to yield point, there is an elastic deformation on metarial, after the yield point with increasing stress, the plastic deformation curve is linear. This kind of behavior generally shown by mostly ductile metals.
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