Sound insulation effect of magnetorheological fluid as a function of magnetic field strength and direction

• Published in: Materials research letters Vol. 10; no. 5; pp. 310 - 317
• Main Authors: Cheng, Hao, Lim, Taeuk, Kim, Sunghoon, Jung, Wonsuk
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 04.05.2022
• Subjects: carbonyl iron powder (CIP); impedance tube; Magnetorheological fluid (MR-F); porous model; sound transmission loss (STL)
• ISSN: 2166-3831; 2166-3831
• DOI: 10.1080/21663831.2022.2050431

We developed a sound absorber using a magnetorheological fluid(MR-F) based on the density and alignment angle of carbonyl iron powder(CIP) chains by the controlling the magnetic field strength and direction. The magnetically arranged CIP lattice structure considerably influenced the sound transmission loss(STL). We used optical microscopy, energy-dispersive X-ray spectrometry, and X-ray diffraction to investigate the STL by varying the magnetic field strength from 0 to 40 mT and the angle from 0 to 30°. The STL was markedly increased (133%) owing to an ∼10-fold increased density and the CIP alignment. These results were verified using the developed MR-F porous model.