Energy Approach to Material Hardness Determination

Energy hardness is defined as energy density of material plastic displacement from the initial surface level. It is convenient to determine it from the kinetic indentation diagram constructed in the coordinates , where is a relative load, is a relative penetration of a spherical indenter. It dhould be note that a relative energy density is equal to multiplied by the parameter where varies within a narrow range for constructional materials used in machine building. A mean relative error in finding energy hardness by this approach does not exceed 5%. It is shown that for the majority of mechanical engineering materials energy hardness is intermediate between plastic hardness and Meyer’s hardness.