Search results for "tribologia"
showing 3 items of 3 documents
Rock friction measurements with stonegrinder apparatus
2016
Liikkuvien tektonisten laattojen välillä kitkan oletetaan olevan suuri. Olettamuksen vastaisia havaintoja on kuitenkin tehty useissa tutkimuksissa. Kuuluisin esimerkki on San Andreasin siirros. Siirrosvyöhykkeellä on matala lämmöntuotto, minkä perusteella on arveltu myös kitkan olevan matala. Syynä matalaan kitkaan voivat olla pyöreät kulumapartikkelit, jotka toimivat kuulalaakereiden tavoin. Kitkan tutkimista varten suunniteltiin ja rakennettiin ainutlaatuinen laite, kivenjauhin (engl. Stonegrinder). Kivenjauhimen tarkoitus on jauhaa kahta kairasydäntä toisiaan vasten ja samalla mitata kitkan muutoksia. Laite mittaa jauhamisen aikana vääntömomenttia, josta laskennallisesti saadaan kitkaker…
Tribological properties of thin films made by atomic layer deposition sliding against silicon
2018
Interfacial phenomena, such as adhesion, friction, and wear, can dominate the performance and reliability of microelectromechanical (MEMS) devices. Here, thin films made by atomic layer deposition (ALD) were tested for their tribological properties. Tribological tests were carried out with silicon counterpart sliding against ALD thin films in order to simulate the contacts occurring in the MEMS devices. The counterpart was sliding in a linear reciprocating motion against the ALD films with the total sliding distances of 5 and 20 m. Al2O3 and TiO2 coatings with different deposition temperatures were investigated in addition to Al2O3-TiO2-nanolaminate, TiN, NbN, TiAlCN, a-C:H [diamondlike car…
The Development and Precision of a Custom-Made Skitester
2021
In the sport of cross-country skiing, equipment has a direct influence on results. Ski teams do extensive testing of different ski base grinds and products on a yearly basis. To achieve reliable results, the quality of methods used for testing skis needs to be taken in to account in addition to factors including the physical characteristics of testing personnel and changes in weather conditions. The aim of this study was to introduce a custom-made skitester, that was developed for testing skis on real snow, in laboratory conditions, and to evaluate its precision. The current skitester is capable of glide testing both classic and skate skis as well as kick simulation for the testing of grip …