EFFECT OF THE MAGNETIC PARTICLES CONCENTRATION ON THE FERRO-OIL’S DYNAMIC VISCOSITY IN PRESENCE OF AN EXTERNAL MAGNETIC FIELD IN THE ASPECT OF TEMPERATURE CHANGES

There is presented an effect of the changes of the concentration of magnetic particles included in the ferro-oil on its dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. The authors assume that the concentration of magnetic particles in ferro-oil can significantly affects its basic physical properties as dynamic viscosity, as well as the operational properties of journal sliding bearings ferro-oil’s lubricated. The equally significant as the above mentioned properties may affect the external environmental conditions of operation, especially temperature changes. In this context, an important technique’s issue appears to determine the principles of selection of optimal concentration of above mentioned particles according to the existing environmental conditions of its operation, or the expectations laid against the operation of the devices. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate-to-plate ” measurement system with an adapter to magneto-rheological studies MRD 180/1T. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for four selected temperature range of 60º, 70º, 80º and 90ºC as regards changes an external magnetic field intensity 0-700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8%