MEASUREMENT OF THE HARDNESS OF HARD COATINGS USING A FORCE INDENTATION FUNCTION

Today the so-called dynamic micro hardness with analysis of the force indentation function is replacing in many cases the conventional Vicke rs hardness measurement for evaluating the hardness of thin films such as coatings for wear protection with thicknesses in the range of seve ral micrometers. This test procedure requires equipment with a numeric ally controlled loading unit and a high resolution mesurement of the i ndentation depth. This contribution shows, using various different exa mples, that the load indentation measurement can solve problems such a s the influence of the operator, but the test conditions should be wel l selected to give comparable and meaningful results. Therefore, this paper analyzes the most important reasons for deviations in practice, and makes suggestions for a standardized test procedure and test docum entation.