Determination of the yield stress of the material by static indentation

Abstract

Determination of the yield stress of the material by static indentation

Kravchuk A.S., Kravchuk A.I.

Incoming article date: 18.09.2018

For the first time, using the simplest model of an elasto-ideally-plastic coating, a relationship between the Meyer hardness and the absolute value of the yield stress of the material under compression was established for all types of indenters used for static hardness testing. The necessity for an accurate determination of the thickness of the layer in the simplest coating model is eliminated, when using the Prandtl bilinear diagram corresponding to an elasto-perfectly-plastic material as the equation of state. If the linear dimension of the test mark of the hardness is equal to 90 percent of the linear dimension of the total contact area, taking into account the elastic deformations, than the Meyer hardness is the absolute value of the compressive yield strength for the material under compression.

Keywords: surface hardness, Meyer hardness, yield strength, ball indenter, conic indenter, pyramidal indentor