An Experimental and Finite Element Approach for a Better Understanding of Ti-6Al-4V Behavior When Machining under Cryogenic Environment.

Roland Bejjani,Mikael Olsson,Charlie Salame

doi:10.3390/ma14112796

Roland Bejjani, Mikael Olsson + Show 1 more

Open Access

https://doi.org/10.3390/ma14112796

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Abstract

Due to increasing demand in manufacturing industries, process optimization has become a major area of focus for researchers. This research optimizes the cryogenic machining of aerospace titanium alloy Ti-6Al-4V for industrial applications by studying the effect of varying the nozzle position using two parameters: the nozzle’s separation distance from the tool–chip interface and its inclination angle with respect to the tool rake face. A finite element model (FEM) and computational fluid dynamics (CFD) model are used to simulate the cryogenic impingement of cryogenic carbon dioxide on the tool–workpiece geometry. Experiments are conducted to evaluate cutting forces, tool wear, and surface roughness of the workpiece, and the results are related to the CFD and FEM analyses. The nozzle location is shown to have a significant impact on the cutting temperatures and forces, reducing them by up to 45% and 46%, respectively, while the dominant parameter affecting the results is shown to be the separation distance. Cryogenic machining is shown to decrease adhesion-diffusion wear as well as macroscopic brittle chipping of the cutting insert compared to dry turning, while the workpiece surface roughness is found to decrease by 44% in the case of cryogenic machining.

Highlights

IntroductionThe modern manufacturing industry needs to meet the growing demands of aerospace production, while adhering to increasingly strict environmental and sustainability constraints, which calls for the optimization of the machining methods used in the industry
The modern manufacturing industry needs to meet the growing demands of aerospace production, while adhering to increasingly strict environmental and sustainability constraints, which calls for the optimization of the machining methods used in the industry.This improvement in productivity, which is defined as the production output in a given time frame, requires increasing the cutting speeds and feeds, which adversely affects the cutting temperatures and causes them to reach temperatures above 900 ◦ C in the case of titanium alloy Ti-6Al-4V [1]
To determine the smallest possible Ds, we considered a physical limitation in our setup, where the closest distance at which the nozzle can be placed without interfering with the tool–workpiece geometry and the flow of chips was found to be 2 cm

Summary

Introduction

The modern manufacturing industry needs to meet the growing demands of aerospace production, while adhering to increasingly strict environmental and sustainability constraints, which calls for the optimization of the machining methods used in the industry. This improvement in productivity, which is defined as the production output in a given time frame, requires increasing the cutting speeds and feeds, which adversely affects the cutting temperatures and causes them to reach temperatures above 900 ◦ C in the case of titanium alloy Ti-6Al-4V [1]. Previous work showed important improvements when cryogenically machining titanium alloys compared to dry cutting. Bordin et al showed a decrease in adhesion on the tool rake face when turning

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