Experimental study and numerical simulation of tribological and mechanical properties of mullite and SiC ceramic matrix composite for journal bearing

This study presents a detailed analysis of mullite and SiC based ceramic matrix composites in comparison to traditional materials used in journal bearings. The research integrates experimental investigations and numerical simulations to analyze the tribological behavior and mechanical properties of these composites. The experimental analysis evaluates the frictional characteristics, wear resistance, microhardness, and thermal stability of mullite and SiC-based composites under conditions relevant to journal bearing applications, comparing them with traditional materials such as Bronze and Babbitt. Results show that the mullite-SiC composites demonstrate a lower friction coefficient of 0.15 and a wear rate of 0.002 g, significantly outperforming the traditional materials. To further understand the material behavior, computational models using finite element analysis simulated the stress distribution, deformation, and frictional characteristics at the bearing interface under varying operational parameters. It predicted no deformation in mullite-SiC composites after two hours of operation, with minimal deformation of 4.6191 mm observed after three hours. Stress analysis revealed uniform stress distribution across the composite, with a maximum stress of 2.93 MPa. Additionally, microstructural analysis using Scanning Electron Microscopy (SEM) identifies minimal abrasive wear and the absence of severe adhesive wear on the composite's surface. The average surface roughness along the wear surface was measured at 2.35 µm. Ultimately, the research outcomes aim to contribute significantly to the advancement of journal bearing technology, facilitating their application in diverse industrial settings where high performance and reliability are crucial requirements.