ABSTRACT
Nanoindentation today is a well-established experimental means to investigate the deformation of bulk materials, thick coatings, biomaterials, and thin films [1-5]. It is almost obvious, therefore, that to understand the nanoindentation behavior and mechanisms of different materials, it is equally important also to know a little about the path that has been charted by numerous researchers [6-35] whose phenomenal contributions have carried us to where we are today. Thus, our focus in this chapter will be the history of indentation.
Well, prehistoric humans also used indentation, albeit unknowingly, by using a sharp pointed stone or an arrow to intimidate, attack, or kill animals and/or enemies. Also, there is the popular comic-strip story about the “walking ghost” who used to leave “a danger signal” impression on the “evil fellow’s” cheek or forehead-a permanent dent or impression on the body. Thus indentation is supposed to leave a permanent mark. It is permanent because it is causing deformation beyond that acceptable by the purely classical elastic limit as provided by Hooke’s law.
