Laser pre-structure-assisted micro-milling of Ti6Al4V titanium alloy

Faramarz Hojati,Dirk Biermann,Bahman Azarhoushang,Amir Daneshi

doi:10.1007/s00170-022-08774-4

Abstract

High flexibility of the micro-milling process compared to nontraditional methods has led to its growing application in manufacturing complex micro-parts with tight tolerances and high accuracies. However, difficulties such as tool deflection, size effect, and tool wear limit the application of micro-milling. In this regard, the role of laser-assisted machining (LAM) is highlighted to prevent mentioned issues through reduction of machining forces and providing the possibility for using higher feeds. Ti6Al4V as a hard-to-machine material is chosen as the workpiece material. Unlike traditional LAM, Ti6Al4V parts were structured using a picosecond laser before micro-milling. The influence of laser structuring at different structure densities on the reduction of machining forces was analyzed at two feeds of 10 and 50 µm/tooth at a constant cutting speed of 35 m/min. A remarkable reduction in cutting forces was observed at both feeds. Additionally, the role of structure density in cutting force reduction is highlighted.

Highlights

Demands for the fabrication of micro-parts with high accuracies are considerably high
The current investigation is allocated to study how considerable is the influence of laser structuring on the machinability of titanium alloy materials with respect to cutting forces
Based on the entire signal in all experiments, force reduction in the x-direction (18.5–49% and 21–43% for feeds of 10 and 50 μm/tooth, respectively) was higher than that in the y-direction (3.5–17% and 11–28% for feeds of 10 and 50 μm/tooth, respectively) that is associated with the domino effect as well as the less structure strength against removing in the x-direction

Summary

Introduction

Demands for the fabrication of micro-parts with high accuracies are considerably high. Micro-milling with great flexibility can be used. The micro-milling process can produce three-dimensional freeform features with micro-level accuracy. A high length to diameter ratio leads to low stiffness of micro-milling tools and increases the probability of tool deflection and the risk of tool breakage. To eliminate this issue, the uncut chip thickness should be reduced for decreasing cutting forces. The uncut chip thickness should be reduced for decreasing cutting forces This could cause poor surface qualities associated with the size effect. Tool wear is another frequent issue that arises in the micro-milling

Methods

Results

Conclusion