Study on Some Factors That Influence the Yield Stress in Kerosene-Based Magnetic Fluids Using an Orthogonal Experimental Design

Magnetic fluid sealing is a novel sealing technology wherein magnetic fluids play a pivotal role in the sealing process. The yield stress of the magnetic fluid directly affectsits sealing performance and is governed by multiple interdependent factors. Conventional approaches that evaluate the effect of a single parameter while keeping other parameters constant are insufficient to fully characterize the relative contributions of each parameter to the yield stress. In this study, we investigate the preparation factors affecting the yield stress of kerosene-based magnetic fluids and propose a parameter sensitivity analysis method based on orthogonal experimental design to determine the optimal combination of factor levels within the studied range. The sensitivity of key preparation factors affecting the yield stress of kerosene-based magnetic fluids was determined via range and variance analyses of the orthogonal experimental data. The factors, ranked in descending order of sensitivity, were surfactant (C18H34O2) dosage, precipitant (NH3·H2O) dosage, and deionized water (H2O) volume. Moreover, the effects of different levels of the same factor were analyzed using multiple approaches. These findings provide a theoretical foundation for optimizing the preparation of magnetic fluids and enhancing their sealing performance.