SOME MOST BASIC BUT IMPORTANT TERMS OF MATERIAL SCIENCE YOU MUST KNOW.
Hardness:
It is the property of material that enables it to resist plastic deformation, penetration, indentation, and scratching.
You must be thinking that why i have used so many property to define the hardness of a material. If yes, then here is your answer for that-
- Hardness has a variety of meanings.
- To the metals industry, it may be thought of as resistance to permanent deformation.
- To the metallurgist, it means resistance to penetration.
- To the lubrication engineer, it means resistance to wear.
- To the design engineer, it is a measure of flow stress. To the mineralogist, it means resistance to scratching, and
- To the machinist, it means resistance to machining.
Methods of measuring hardness:
- Rockwell hardness test
- Brinell hardness test
- Vickers
- Knoop
TOUGHNESS:
- Toughness is a measure of the amount of energy a material can absorb before actual fracture or failure takes place.
- The toughness of a material is its ability to withstand both plastic and elastic deformations.
- It also describes the way a material reacts under sudden impact.
- For Ex: If a load is suddenly applied to a piece of mild steel and then to a piece of glass the mild steel will absorb much more energy before failure occurs. Thus, mild steel is said to be much tougher than a glass.
Methods of measuring:
- Charpy test
- izod test
RESILIENCE:
- It is the ability of a material to absorb energy when it is deformed elastically, and release that energy upon unloading (as in spring).
- The maximum energy which can be stored in a body up to elastic limit is called the proof resilience
- The quantity gives capacity of the material to bear shocks and vibrations.
STIFFNESS:
- The resistance of a material to deflection is called stiffness or rigidity. Steel is stiffer or more rigid than aluminium.
- Stiffness is measured by Young’s modulus E. The higher the value of the Young’s modulus, the stiffer the material.
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