Magnetic nanomaterials in the use of friction problems

Abstract

Nanocrystalline materials are finding increasing application everyday. One possible application is modification of surfaces or oils with magnetic nanoparticles. Two aspects are used in serial production. Firstly, oils are enriched with iron oxide nanoparticles and form suspension - so called ferrofluid. Structural defects on the steel surface form magnetic field gradients, which attract particles from oil. At defected place collections of nanoparticles are formed and they cover defects. Being very small particles can fill even tiniest splits (up to 0,01 pm) and prevent further cracking. Secondly, external magnetic field can change viscosity of oil. These properties allow creation of dampers with controllable resilience or control of the rotation speed of shaft. The use of nanocrystalline particles is very perspective and requires more research in order to investigate magnetic properties of nanoparticles, and how these properties depend on the particle size and mobility (Brownian motion)Vytauto Didžiojo universitetasŽemės ūkio akademij