Tribološke lastnosti polimernih materialov za vodno hidravliko - Tomše, Matija (M. Tomše, 2021)
Voda kot tekoči medij v hidravličnih sistemih omogoča hitre odzive, majhne tlačne izgube, poleg tega pa je tudi okolju prijazna. Namen naloge je bila določitev ustreznega para materialov za konstrukcijo glavnih komponent vodno-hidravličnega ventila. Ustrezna izbira bi pomenila učinkovito delovanje in podaljšano uporabno dobo ventila. Pojav trenja in posledično obrabe sta bila ključnega pomena pri sami izbiri materialnih parov, zato smo v okviru naloge izvedli številne tribološke preizkuse. Drsne koeficiente trenja posameznih parov materialov smo določili na podlagi preizkusov s tribometrom. Obrabe pa smo analizirali s pomočjo optičnega interferometra. Za najustreznejši material se je izkazal polieter-eter-keton utrjen z 30% ogljikovimi vlakni (PEEK CA30), saj je imel na podlagi opravljenih preizkusov najnižji koeficient trenja, kot tudi najmanjšo obrabo. Preizkusili smo tudi polimer polioksimetilen (POM), ki je cenejša alternativa materialu PEEK CA30. Izkazalo se je, da ima tudi POM relativno nizek koeficient trenja, kot tudi nizko obrabo. The use of water in hydraulics systems allows us to achieve fast responses, minimize pressure loss in hydraulics and most importantly it is extremely environmentaly friendly. The task was to determine which material would be best for the construction of the main components of our water-hydraulic valve. The best choice would increase the working efficiency and extend the life of our valve. The appearance of friction and thus wear were te most important factors in choosing materials. For this reason we conducted several tribological tests during our test. Based on experiments with our tribometer, the coefficients of sliding friction were determined for each of two materials. The wear was analyzed with our optical interferometer. The most suitable pair of materials proved to be polyether-ether-ketone with 30% carbon fibers (PEEK CA30), as it exhibited best mechanical properties. It had the lowest coefficient of sliding friction and wear. However, we also considered the cost of materials. Polyoxymethylene (POM) proved to be the cheaper alternative, as it also had relatively low coefficient of sliding friction and low wear.