International Research Journal of Engineering and Technology ( I RJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 04 | July-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET ISO 9001:2008 Certified Journal Page 2023 A STUDY ON MAGNETO RHEOLOGICAL FLUIDS AND THEIR APPLICATIONS Suryawanshi Ravishankar 1 , Rayappa Mahale 2 1 UG Student, Department of Mechanical Engineering, D. Y. Patil School of Engineering Academy, Pune, Maharashtra, India. 2 Assistant Professor, Department of Mechanical Engineering, D. Y. Patil School of Engineering Academy, Pune, Maharashtra, India. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Magneto rheological fluids have received widespread attention as smart materials due to their tunable properties. A magneto rheological fluid consists of three key components including, soft magnetic particles, carrier liquids and additives. This paper details the characteristics, composition, and rheological principle of magneto rheological fluids, working principle of magneto rheological fluid devices, and their applications in other engineering arenas. The aim is to provide a basic understanding of magneto-rheological components and technology to the readers. Key Wor ds: Magneto Rheological Fluid, MR Dampers, Off State Viscosity, Thixotropic Additives, Carbonyl Iron Particles etc. 1. INTRODUCTION Magneto rheological fluids commonly known as MR fluids are suspensions of solid in liquid whose properties changes drastically when exposed to magnetic field. It is this property which makes it desirable to use in different vibration controlling systems. Magneto-rheological fluids consist of micron sized polarizable particles in a liquid. Application of a magnetic field changes MR fluid from a liquid state to a semi-solid state, proportional to the strength of the field applied. Magneto-rheological fluid has the extremely widespread application prospect in many fields including aerospace, automotive industry, hydraulic transmission, biotechnology and medical because of its characteristics of continuous, reversible, rapid and easy control [6]. 1.1 Principle of Operation Applying a magnetic field to magneto Rheological Fluids causes particles in the fluid to align into chains. Micro particles are magnetized to produce orderly movement when an external magnetic field is applied, this movement generating at the beginning of micro particles are magnetized and finishing until reaching a relatively stable state, forming a fixed structure. Fig 1. Behavior of MR fluid under Magnetic Field Fig 2. Behavior of MR fluid under Alternating Magnetic Field The structure of particles in an MR fluid gradually changes when an alternating magnetic field is applied. The leftmost picture shows an MR fluid after 1 second of exposure to a fast-changing magnetic field. The suspended particles form a strong, fibrous network. The pictures to the right show the fluid after 3 minutes, 15 minutes and 1 hour of exposure. The particles have formed clumps that offer little structural support. 2. Selection Criteria for MR Fluid Components The change in one or more components or in their properties influences the MR effect. The selection criteria for different MR fluid components are given below: