Experimental study on correcting the contour error of a rotary surface machined by electrochemical mechanical machining

Effectively improving the precision and surface quality simultaneously is the goal of manufacturing technology. Due to the excellent surface quality of machined workpieces, electrochemical mechanical machining (ECMM) has been widely used as a polishing method for different components. Recent studies have found that ECMM can not only reduce surface roughness, but also improve precision to some extent. Under precision machining conditions, the roughness error value is close to the precision error value; therefore, leveling the roughness can improve the precision. To explore whether correcting the contour error of a rotary surface is caused by roughness improvement or the fundamental changes of its profile, orthogonal experiments were carried out to verify that electrochemical parameters had more influence on the precision than mechanical parameters. The machining current was the most important factor for accuracy. On this basis, an experiment was carried out under changing cathode coverage, and the results showed that component precision was affected by the cathode coverage on the workpiece surface. Specifically, the contour macro morphology exhibited a remarkable change with increasing cathode coverage, and this change was independent of roughness. This result demonstrated that under the same mechanical and electrochemical parameters, the contour error, which can be attributed to error homogenization, could be corrected by enlarging the influence area of the cathode on the workpiece surface. Therefore, ECMM can not only polish the part surfaces, but also fundamentally improve machining accuracy, showing promising application prospects in the trans-scale precision shaping of high-precision components.