The use of a modern method of designing experiments in ball-cratering abrasive wear testing

Abstract

This article presents an outline of a method of planning an experiment developed by Taguchi for the optimisation of processes and as an example of its application in the optimisation of parameters of a ball-cratering method. Abrasive wear tests were performed on chosen antiwear physical vapour deposition coatings with the optimum work parameters of friction node. (The test friction node is created by the rotating ball and the immobile sample disc that is pressed against it and an abrasive slurry is drip fed into the contact zone.) Then the factor of resistance to abrasive wear was calculated based on the evaluation of their resistance to abrasive wear. The Taguchi optimisation method was used in order to devise and verify the methodology of the abrasive wear research of physical vapour deposition coatings deposited using cathodic arc evaporation on two differently prepared substrates. A series of resistance tests to abrasive wear performed using ball-cratering method was conducted in accordance with the test plan based on the Taguchi design. The variable test parameters were load, the speed of ball rotation and sliding distance. A measuring device, an optical microscope, was used to take pictures and measure the diameters of the wear traces visible in the form of craters received after the performance of tribological tests. The purpose of this research was to devise a method for testing the resistance of antiwear physical vapour deposition coatings deposited on tools and machine parts to abrasive wear (performed using the ball-cratering method) by applying the Taguchi optimisation method. The experiments were carried out using the combination of tribological test parameters based on the nine experiments (L9) using Taguchi orthogonal design with variable three test parameters of load, the speed of ball rotation and sliding distance. The results of the abrasive wear test performed using ball-cratering method on duplex and non-duplex coatings were successfully verified using the Taguchi optimisation program. Optimisation of the tribological test parameters based on the Taguchi method has been found to be very efficient and convenient for the investigation of the abrasive wear rate of the duplex and non-duplex coatings.