DESIGN, BUILDING AND VALIDATION OF A BALL-CRATERING WEAR TEST EQUIPMENT BY FREE-BALL TO MEASURE THE COEFFICIENT OF FRICTION

The purpose of this work is to present a ball-cratering equipment configuration to measure the coefficient of friction. Two load cells were used to measure, in real time, the “normal” and “tangential” forces during the experiments to calculate the coefficient of friction. Micro-abrasive wear tests were conducted on an AISI H10 tool steel specimen, with a ball of AISI 52100 steel and an abrasive slurry, prepared with SiC and distilled water; different values of normal force and sliding distance were defined for the wear experiments to investigate and validate the constructed machine. The results showed that due to test conditions, it was observed the occurrence of rolling abrasion. The equipment showed excellent functionality and reproducibility, in terms of formation of the wear craters and measurement of the coefficient of friction.