Precision Surface Finishing and Functional Performance Enhancement of Spline Shaft Using Magnetorheological Process

The lifespan of a spline shaft during its operation is significantly affected by how pressure is distributed across its surface. Achieving a consistently smooth finish on the teeth of the spline shaft is highly beneficial because it promotes a uniform distribution of pressure. This uniformity helps to minimize stress concentrations, which typically lead to increased wear and a longer lifespan for the shaft. This study focuses on using a new magnetorheological (MR) method to finely finish the surface of spline shafts. A single electromagnetic MR finishing setup, using interchangeable tool cores, processes both the external and internal profiles of the spline shaft. Response surface methodology (RSM) was used to optimize process parameters for achieving the desired fine finish. Significant results were obtained: the external profile’s surface roughness was reduced from 0.27μm to 0.02 μm, and the internal profile’s surface roughness was improved from 0.3 μm to 0.029 μm. To further evaluate the effectiveness of this MR finishing process, tests were conducted to analyze the surface characteristics and microhardness of the spline shaft. The findings indicate that the MR finishing process improves pressure distribution and extends the service life of the spline shaft.