Optimisation of Planning Parameters for Machining Blade Electrode Micro-Fillet with Scallop Height Modelling.

Yue Liu,Bing Wang,Zhanqiang Liu,Wentong Cai,Yukui Cai,Guoying Li

doi:10.3390/mi12030237

Abstract

Aero-engine blades are manufactured by electroforming process with electrodes. The blade electrode is usually machined with five-axis micromilling to get required profile roughness. Tool path planning parameters, such as cutting step and tool tilt angle, have a significant effect on the profile roughness of the micro-fillet of blade electrode. In this paper, the scallop height model of blade electrode micro-fillet processed by ball-end milling cutter was proposed. Effects of cutting step and tool tilt angle the machined micro-fillet profile roughness were predicted with the proposed scallop height model. The cutting step and tool tilt angle were then optimised to ensure the contour precision of the micro-fillet shape requirement. Finally, the tool path planning was generated and the machining strategy was validated through milling experiments. It was also found that the profile roughness was deteriorated due to size effect when the cutting step decreased to a certain value.

Highlights

The machining precision and surface quality of the blade electrode have a significant influence on the machining quality of engine blades in the electrotyping process of aeroengine impeller blades
The streamline machining strategy is divided into two types, namely, streamline and isometric, which correspond strategy makes the cutting tool move along the streamline according to the shape trend
Andand contour accuracy of the of samples were observed with laser scanning confocal microscope (LSCM)

Summary

Introduction

The machining precision and surface quality of the blade electrode have a significant influence on the machining quality of engine blades in the electrotyping process of aeroengine impeller blades. The machining of the micro-fillet on a blade electrode is challenging because of its high precision requirement, small size and considerable curvature variation. The tool path parameters in machining programming, especially the tool tilt angle and cutting step, affect the scallop height and surface formation process, determining the profile roughness. The scallop height model [4] proposed in 1995 can be used as a prediction model of surface roughness.

Methods

Results

Conclusion