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Chapter VIII Micro-hardness studies…
Chapter VIII
Micro-hardness Studies of Pure and Amino Acids Doped
8.1 Introduction:
KDP Crystals
The concept of hardness varies with situation. A convenient definition
is generally given by one’s own perception and thoughts; the hardness in
terms of sawing, drilling or filing or the hardness in terms of wearing a job as a
machinist thinks; while an engineer grades his material on the basis of the
depth of penetration of a hard indenter as it is forced into a surface with
specific force.
The resistance offered by material to indentation by a relatively
harder body is known as hardness. The most common method of determining
hardness consists of indenting a solid surface by a loaded indenter of a
definite geometrical shape and measuring the contact area between the
indenter and the material. The ratio of the load and the contact area is the
experimental definition of hardness. Most of the techniques for the
determination of hardness are essentially means of giving a quantitative value
to the materials ability to resist load deformation [1]. Hardness is defined
alternatively as resistance against lattice destruction [2] and also stated as the
resistance offered by a solid to permanent deformation.
Nevertheless, attempts have been made to define hardness in
numerous ways such as: “Hardness is like the storminess of the sea, easily
appreciated but not readily measured (or defined) [3]”. “The hardness is not a
single property but rather a complex of mechanical properties and at the same
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