A three-point method for evaluating the tilt status between the indenter axis and the sample surface

Non-perpendicularity nanoindentation experiments commonly exist in previous research work and affect nanoindentation results. In this design note, a new measuring method named the three-point method is proposed to evaluate the tilt status between the indenter axis and the sample surface. The measuring principle is addressed in detail. By the proposed measuring method, the tilt status between the indenter axis and the sample surface can be evaluated by the selected three points on the sample surface. A measuring example is given to verify the feasibility of the three-point method. This method is independent of other measuring equipment and it has the potential to be used in commercial nanoindentation instruments for evaluating the tilt status between the indenter axis and the sample surface.