Flexible CNC polishing process and surface integrity of blades

The surface integrity of aero-engine blades directly affects its mechanical behavior. To improve the surface integrity and address the problem, that is, the blade is mainly polished manually, a flexible polishing process was proposed and surface integrity was investigated. First, flexible polishing technology and the machine tool that the authors researched and developed were introduced. Second, a polishing experiment was conducted on a TC4 titanium alloy blade. Finally, the surface integrity before and after polishing was measured and the results were compared and analyzed. Results showed that the knife marks, pits, unevenness, and other defects of the blade surface were effectively removed through flexible polishing; the surface residual compressive stress was reduced from 483 MPa to 397 MPa; the surface roughness was reduced to Ra 0.4 μm; the surface micro-hardness increased by 18 HV; and the surface metamorphic layer caused by milling was removed. Flexible polishing effectively improved the surface quality without affecting the depth layer quality of the workpiece.