Hardness of materials (Metals, Plastics and Ceramics) (Theory and Practice)

Hardness is a mechanical property of materials. It is defined as the resistance of a material to deformation in indentation or scratching. There are many types of hardness tests which we can perform on materials. Each test has its own procedure and the shape of the indenters. Hence, hardness is generally given as hardness number. The more fundamental way of defining hardness is the ratio of force of indentation to the projected are of the indent produced. The indent or the indentation marks is imaged and the projected area measured after performing the test using a microscope. Hence, this value of hardness uses the plastic ( and localized fracture) behaviour of the material. Hardness in the basic method of measurement is given in the unit of MPa, which is the same as the unit of pressure. (Your comments and questions are welcome). Vickers Hardness; Meyer Hardness; Scratch Hardness; Brinell Hardness; Nanoindentation; Microhardness; Materials Science and Engineering; Mechanical Engineering; Tribology