Diamond tool cutting edge measurement in consideration of the dilation induced by AFM probe tip

•AFM imaging and reconstruction algorithm are presented.•Measuring method to eliminate the dilation effect of AFM probe tip is presented.•Dilation effect of AFM probe tip on the diamond tool measurement is important.•The profile touched by the probe tip can be reconstructed perfectly. Measurement of diamond cutting edge is of great importance in ultra-precision machining. Atomic force microscope (AFM) that takes advantage of its three-dimensional (3D) imaging in nanoscale becomes an indispensable means to acquire the 3D surface morphology of the diamond tool cutting edge. However, the dilation induced by AFM probe tip in diamond tool cutting edge measurement is a key error source in cutting edge evaluation, especially for the very sharp edge. In this paper, analysis and elimination method of this dilation effect are presented based on the principle of AFM imaging in terms of mathematical morphology theory. Our work effectively improves the evaluation accuracy of diamond tool cutting edge, which is beneficial to the diamond tool manufacture and selection in ultra-precision machining.