Hardness

: For the mathematical concept of the difficulty of proving a conjecture, solving an equation, etc., see computational complexity theory.

Related Topics:
Mathematical - Computational complexity theory

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In materials science, hardness is the characteristic of a solid material expressing its resistance to permanent deformation. Hardness is measured by Mohs Scale

Related Topics:
Materials science - Solid

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There are three principal operational definitions of hardness:

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• Scratch hardness
• Indentation hardness
• Rebound, dynamic or absolute hardness
 
Hardness: Scratch hardness ►