Deformation error compensation in 5-Axis milling operations of turbine blades

Abstract

The precision and performance of machined flexible parts are under influence of deformation errors during end milling operations. Thus, prediction and compensation of deformation errors during milling operations of flexible parts can provide a key tool in accuracy enhancement of part production. In this study, an improved virtual machining system is proposed in order to assess and compensate deformation errors caused by cutting temperature and forces in 5-axis milling operations of flexible parts. The improved Johnson–Cook model is utilized to investigate the cumulative impact of strain rate and deformation temperatures on flow stress during milling operations of turbine blade. To estimate deformation errors caused by cutting forces and temperature on the workpiece and cutting tool, the finite element analysis is then applied. As a result, volumetric vectors of deformation error at each cutting location along the machining pathways are then generated in order to be compensated within new compensated machining tool paths. Thus, the deformation error created by cutting forces and temperature on the workpiece and cutting tool are compensated in order to enhance accuracy during 5-axis milling operation of flexible turbine blades. Experiments are carried out using a 5-axis CNC machine tool and errors are quantified using a CMM to verify the developed strategy in the study. As a consequence, precision of machining operations on flexible turbine blades can be enhanced by employing the developed virtual machining system in the study.