V.V. Sokolov, M.I. Osipov
Moscow State University of Instrument Engineering and Computer Science, Russian Federation
pp. 300 - 303
Keywords: magnetic nanofluids, ultrasonic velocity, non-destructive testing
The use of the magnetic nanofluid as the bonding medium find an ever increasing application in ultrasonic non-destructive testing method. A thin layer of magnetic nanofluid which is adhered on the transducers face with a permanent magnet enhance the ability of movement and provide good bonding for transducers. It is useful in the design of such ultrasound systems to know the physical properties of magnetic nanofluids. Measurements of the temperature dependence of the ultrasonic velocity, density, viscosity and surface tension of water-based, dodecane-based, kerosene-based, antifreeze-based magnetic nanofluids have been made. It is shown that ultrasonic velocity nonlinear decreases while concentration of magnetic particles increases. It can be explained in terms of inertial properties of a magnetic nanofluid because its elastic properties depend only the kind of carrier fluid used . Using the results of the hydrodynamical analysis and these experimental data we evaluated the magnetic fluid losses when the transducer is moving along the tested surface. The obtained results can be use for the choice of an optimum type of magnetic nanofluid in the design of ultrasonic transducers.