Verification of Vickers indenter geometry by means of three-dimensional coordinate measurement

Abstract

The paper describes an accurate but practical method of the verification of a Vickers hardness indenter geometry. Three-dimensional coordinates of selected points on the surface of four faces of a Vickers indenter are measured with the laser probe 3D profile measurement instrument. The measurement is made with respect to the datum of the indenter so that the misalignment of the axis of pyramid will not interfere to the verification results of geometry. The directions of pyramid faces are analyzed with equations of the best-fit planes to data points estimated by the least-squares algorithm. The flatness of faces is also evaluated as the range of orthogonal distances of data points from the fitted plane. The results show that the geometry of a Vickers indenter is successfully verified with proposed method and the resolution and repeatability of the method are good enough to verify calibration-machine-grade indenters.