In-situ-Vergleich wälzbeanspruchter Diamant-und diamantähnlicher Kohlenstoffschichten durch die Akustische Emission

Slip-rolling tests were performed on diamond coatings and diamond like coatings deposited on SSiC-substrates as well as 100Cr6 steel substrates against various counter bodies under paraffin oil lubrication or under non-lubricated conditions. The average specific pressure was initially set between P m = 1,0 GPa and P m = 1,5 GPa. During these tests the signals of the acoustic emission (AE) were recorded. It turned out that the onset of the failure of a coating was indicated by a temporarily increase in the number of hits (AE-activity). If a continuous, intense AE-activity was recorded, the respective images taken with an optical microscope showed that the DLC coating had lost its wear protective function. Using the intensity of the hit rate in combination with slip-rolling tests carried out on uncoated reference samples under similar conditions, the origin of different AE-signals could be deduced.