Study on design, manufacture, and cutting performance of circular-arc milling cutters for machining titanium alloy

Chen Tao,Lu Yujiang,Wang Guangyue,Li Rui,Liu Gang

doi:10.1007/s00170-021-07915-5

Abstract

Titanium alloy is widely used for manufacturing structural parts of high-end equipment due to its excellent mechanical properties, despite difficulty in being machined. Nowadays, titanium alloy parts are mostly machined by ball-end milling cutters (BEMC), but the cutting edge structure of the BEMC limits the improvement in machining efficiency and surface quality of the parts. In this paper, a circular-arc milling cutter (CAMC) with large-curvature cutting edge was proposed; the differential geometry method was used for establishing the geometric model for the contour surface of the CAMC and the mathematical model for the spiral cutting edge line; the conversion matrix between grinding wheel and workpiece coordinates was introduced to derive the equation of grinding wheel trajectory when the rake face of the CAMC was ground; the self-designed CAMC was ground and tested in accuracy. The comparative research was conducted experimentally on the side milling of titanium alloy TC4 with the CAMC and BEMC, and consequently the variation laws of milling forces, wear morphology, and machined surface quality were obtained about the two types of milling cutters. The results indicated that the CAMC can effectively reduce the main milling force and keep the milling process stable. Moreover, the CAMC was worn slower and produced better surface quality than the BEMC.

Highlights

Titanium alloy has become preferable material for key parts in the aerospace industry due to its merits such as high strength, strong corrosion resistance and low-temperature performance [1, 2]
The frequently used ball-end milling cutters (BEMC) have large-curvature cutting edge, and tend to shrink milling step to ensure good machined surface quality, but this decreases the efficiency of machining titanium alloy and increases the manufacturing cost more or less[3,4]
The research was conducted on design, manufacture and cutting performance of circular-arc milling cutters (CAMC) for machining titanium alloy

Summary

Introduction

Titanium alloy has become preferable material for key parts in the aerospace industry due to its merits such as high strength, strong corrosion resistance and low-temperature performance [1, 2]. Chen et al [11] proposed new mathematical models and grinding methods of BEMC based on the orthogonal spiral cutting edge curve It was found through the grinding experiments that both rake face with equal rake angle and flank face with equal clearance angle improved effectively chip removal conditions and machining performance of BEMC. Combined with the design idea for integration of tool design and manufacture [25], this paper employed the differential geometry method for designing a circular-arc milling cutter (CAMC) with large curvature, resolving the contradiction of the above novel cutters between edge radius of ball end and overall tool rigidity This provides a new idea and method for the design and manufacture of milling cutters for machining titanium alloy

Design of CAMC

Manufacture and detection of the CAMC

Comparative experiments on side milling of TC4

Conclusion