Thesis Topic

Constitutive modeling of the mechanical behaviour of additive manufactured Inconel 718: application to machining simulation
Titre en français

Abstract

Additive manufacturing (AM) combined with a subtractive process (such as machining) enables the creation of parts with high complexity, tight tolerances, and good surface finishing. AM enables complex geometries to be generated, while machining produces better geometric accuracy and surface finishing quality than AM. A recent review on AM and surface finishing processes highlighted the fact that the limited number of research works on AM parts surface finishing is not yet able to promote the adoption of AM by several industrial sectors for an efficient, sustainable and profitable use without compromising the product quality. Therefore, there are considerable research and development opportunities in this area. This project is centred on AM using Selective Laser Melting (SLM) process followed by machining to produce high quality parts in Inconel 718 without applying post-heat treatment. This can be a challenge since heat treatment is usually applied to improve the mechanical properties of AM parts, and to relieve the high residual stress (RS) levels in the Inconel 718. These RS are caused by the rapid cooling during AM. They can affect the machining process and also the mechanical behaviour of AM Inconel 718. The project aims to develop an anisotropic constitutive model combined with an advanced numerical method to accurately simulate the machining process of SLM Inconel 718. The anisotropic constitutive model should be able to accurately predict the mechanical behaviour of SLM Inconel 718 in machining. Therefore, it should account for most influencing factors in both material flow stress and damage of SLM Inconel 718, including: strain-rate, temperature, state of stress (stress triaxiality and Lode parameters), microstructure and RS.

Doctoral advisors

• Guillaume FROMENTIN - Director,
• José OUTEIRO,
• Hélène BIREMBAUX,
• Dominique COTTON.

Partner(s)

• LEM3
• ARMINES

Project

PhD in the frame of the CENTURION project

Funding

• ANR

Start

1st of November 2023

Expected end

1st of November 2026