Rheological Characterization of Magnetorheological Fluids for Brake Applications: An Experimental Procedure

This work focused on the development of a complete laboratory procedure for the rheological characterization of magnetorheological fluids (MRFs) by combining information gained from the literature and practical work performed in the laboratory. The procedure developed involves all the experimental stages for a comprehensive analysis, starting from the sample preparation, choice of the optimal measuring system, definition of the test, and rheometric parameters for the execution of an accurate and reliable analysis. Magnetorheology is a critical approach for studying the field-dependent properties of MRFs; however, measurement errors, often stemming from inappropriate rheometric test parameters, pose significant challenges. Additionally, sedimentation, caused by the large density mismatch between magnetic particles and the carrier fluid, presents a major obstacle that can compromise the analysis. Extensive work was performed for selecting the test parameters as well as defining the most relevant type of analysis to conduct with the defined procedure for the definition of the essential properties of an MRF for braking applications. This work is essential for the development of accurate card material for simulation tools, paving the way for broader utilization of MRFs in cutting-edge technologies.