Experimental determination of the compression behavior of RTV silicone rubber-based magnetorheological (MR) materials under static loading

In this study, MR elastomer (MRE) materials were produced using seven different types of silicone rubber and five different types of magnetically sensitive ferromagnetic powders. The MRE materials were obtained in three states: pure, isotropic (homogeneous), and anisotropic (aligned). Compression tests were conducted using a uniaxial testing machine, with engineering stress–strain curves, tangent modulus, and MR-strain behavior graphs generated, considering powder ratio, powder type, and hardness values. The goal was to investigate the positive effects of magnetic field influence on these parameters and how the alignment state affected the stress performance of the materials. As a result, the highest stress increase at 10% strain was observed in materials containing 40% powder, with magnetic field comparison showing the most significant results. With the EM powder type at a 30% powder ratio in the isotropic state, a 563% increase in stress was obtained. Among the matrix materials with the same hardness, the most robust material was determined to be the MM240 TV with a Shore hardness of 40. Furthermore, the most significant increase in tangent modulus under the influence of the magnetic field was observed in vertically aligned materials. Compared to the pure material, a 3127% increase was found at 0.57% strain in vertically aligned samples. In materials with Shore hardness of 2, using Basf CN powder at 10–40% powder ratios, the highest relative MR effect was observed at a 20% powder ratio. The stress increase for vertically aligned samples compared to the pure state was 1274.6% at 0.27% strain. When comparing the relative MR effect of materials with Shore hardness between 10 and 59, the largest increase was obtained from the Sorta Clear matrix material.