Thesis Topic

Study of distortion mechanisms in machined nickel alloy parts: effect of phase change (debriding/turning/bridging) and coupling with distortions linked to other mechanisms
Étude des mécanismes de distorsions de pièces usinées en alliage de nickel : effet du changement de phase (débridage/retournement/rebridage) et du couplage avec les distorsions liées aux autres mécanismes

Abstract

In the aeronautical industry, conventional machining processes continue to occupy an important part of the manufacturing ranges of high value-added parts. This is particularly the case for many nickel alloy rotating parts present in the hot parts of a turbojet. This type of alloy is well suited to severe thermomechanical conditions encountered in flight but has low machinability. This poor machinability leads to high cutting tool costs and the severity of the cut can alter the surface integrity. First, the objective is to improve the control of part deformations so as to systematically meet the dimensional specifications associated with the finished product in order to minimize the number of scraps. Second, the ability to accurately predict part deformations will help to achieve the objective of machining «right from the first shot»: without further machining or ex post derogations. This will make it possible to optimise industrial performance during the industrialization phase and then during production, by defining the number of machining operations, the tool paths, the number of machine layouts or assemblies required, as appropriate, etc. Thirdly, the problem of deformation of parts implies knowledge of the stress field and its evolution in the part throughout the machining process. This information can help to advance the prediction of the service life and service life of these parts to ensure the requirements set by the design firms.

Doctoral advisors

• Guillaume FROMENTIN - Director,
• Fabien VIPREY,
• Eric MONTEIRO,
• Théo DORLIN,
• Habib KARAOUNI

Partner(s)

• Safran Tech

Project

N/A

Funding

• CIFRE

Start

1st of January 2022

Expected end

15th of January 2025