A repair strategy based on tool path modification for damaged turbine blade

Turbine blade plays an extremely important role in the aerodynamic performance of aero-engine. And the repair of damaged turbine blades is of great interest for aerospace industries due to continual increase in raw material and manufacturing costs. This manuscript presents a new repair strategy for damaged turbine blades based on tool path modification. The strategy basically involves three crucial procedures: rigid registration of nominal curve and measured points adjacent to damaged region, B-spline approximation of residual errors based on feasible region, and modification of the tool paths used for repairing machining. Rigid registration of nominal curve to measured points is accomplished using improved ICP algorithm adjacent to damaged region. B-spline approximation of residual errors is used to calculate smooth modification amount corresponding to cutter location points. And finally, modified tool paths are used for repair machining, including grinding and polishing. Tip repairing of a rotor turbine blade has been successfully performed to demonstrate the effectiveness of the proposed methodology. The error of repair machined trace between the repaired area and undamaged area is within 0.01 mm which commendably meets the repair machined requirement. And the repaired results have shown that the repairing strategy proposed in this paper is a reliable solution for repairing tip of turbine blades and can guarantee a surface smooth restoration with higher accuracy.