Geometric characteristic modeling for flexible contact of sanding wheel–polished complex surface

The blade profile of a milled aeroengine blisk is a spatial free-form surface with significant curvature changes, which seriously restrict the quality uniformity of the polished surface. To investigate the geometric characteristics of the flexible contact of an elastic grinding tool–polished complex surface, a polishing process equipment integrating “CNC machine tool + flexible grinding head + elastic grinding tool” was used in this study. Through an analysis of the geometric theory, a mathematical model for the boundary between the sanding wheel and polished surface in the contact zone, a mathematical model for the compression amount in the contact zone, and a mathematical model for the removal depth were established to conduct simulation and polishing tests. The results show that both the compression amount of the sanding wheel and curvature radius on workpiece surface have remarkable effects on the boundary and removal depth in the contact zone; the feed speed, rotation speed, and particle size of the sanding wheel have no bearing on the boundary in the contact zone, but they can influence the removal depth markedly. The simulation results are basically consistent with the test results, proving that the established models are reliable and applicable to geometric characteristic prediction of the elastic grinding tool–polished complex surface.