TRIBOLOGICAL BEHAVIOUR OF ABRADABLE COATINGS OBTAINED BY ATMOSPHERIC PLASMA SPRAYING (APS)

摘要

Actually abradable coatings obtained by thermal spraying are currently used in aeronautical industry. They improve the turbines tightness increasing in that way, their yield. The most relevant property of this kind of coatings is its easy machinability. They have good friction properties due to the lubricant phases such as graphite or polyester and could be used for surface engineering. To optimizate abradable coating it is necessary to study the wear mechanims implied in tribological processes. In the Thermal Spray Center of the Universitat de Barcelona, AlSi-Polyester, AlSi-Graphite and Ni-Graphite coatings have been studied. Their tribological study includes Ball on Disk (BOD) test (according to ASTM G99-90) to determinate the coating friction coefficient. The wear mechanism is determined by the study of the wear track by means of scanning electron microscopy (SEM) and Scanning white light interferometry (SWLI). Main common wear parameters are reported and compared to the steel substrate.