고체역학실습 레포트 3

Objectives
Hardness is the resistance of a material to localized plastic deformation. It is an important mechanical property of a material, so it is necessary to understand the way to investigate hardness for mechanical engineers. In this experiment, we will learn the definition of hardness and one of hardness test, which is called the Vickers hardness test. Also, finally we will figure out the Vickers hardness of SM20C specimen.

Theory
First of all, we have to know what the Vickers hardness test is. There are several types of hardness test, for instance, Rockwell, Brinell, Vickers hardness test or etc. It is typically categorized by the objective and the type of an indentation tip, or an indenter. We will focus on the Vickers hardness test. A pyramid-shaped diamond indenter with 136 angle between opposite surfaces is used in the Vickers hardness test. Once we apply the load on the SM20C specimen, an indentation will be made. (Figure 1.)