[M/F] Research and development engineer for the development of a thermo-mechano-optical test bench

Organisation/Company

CNRS

Department

Institut Clément Ader

Research Field

Engineering » Materials engineering
Physics » Acoustics

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

16 Feb 2024 – 23:59 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

35

Offer Starting Date

1 Mar 2024

Is the job funded through the EU Research Framework Programme?

H2020 / ERC

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Metallic/intermetallic structural materials operating at high temperatures (650°C-1200°C) in harsh environments are commonly subject to in-service surface reactivity, i.e. oxidation and corrosion. This problem is encountered in a number of industrial applications, particularly where high temperatures, mechanical stresses and highly corrosive atmospheres are combined (power plants, aeronautical turbines, etc.) [1]. Environmentally-assisted degradation modifies both the surface of materials and their properties in volume due to selective consumption of elements involved in the surface degradation process and/or diffusion of oxidizing elements (e.g. sub-surface layer depleted in hardening precipitates for nickel-based superalloys due to consumption of aluminum to form Al2O3, etc. [2, 3], oxygen/nitrogen enriched brittle layer in Ti and TiAl alloys due to O and N solubility [4, 5], etc.). The material affected by oxidation thus presents a gradient of chemical composition, microstructure and physical properties. This gradient of microstructure and properties evolves over time as a result of oxide growth and diffusion processes.

Each family of metallic/intermetallic materials reacts differently to so-called “stress corrosion”, but also to corrosive/oxidative deformation. However, all materials are potentially affected by these mechanisms due to the concomitant effects of surface reactivity, microstructure evolution and deformation. Despite the negligible scale of physical, chemical and metallurgical gradients (from 0.1 to 100 micrometers below the surface) compared to the dimensions of structural components, the variability of mechanical behavior within the gradient often leads to premature damage and progressive component failure [6]. This evolution and degradation of materials could be included in so-called “stress corrosion-assisted cracking”, which has been studied for decades for all structural materials used at high temperatures. However, industrial and ecological motivations for using structural materials under increasingly extreme and severe conditions are pushing them to their performance limits. The synergy between the localization of inter- and intra-granular deformations and surface reactivity/diffusion processes favors unexpected damage and high variability in the service life of structural components exposed to “too high temperatures – too high stresses (cyclic and/or constant)” [7]. A better understanding of the elementary thermo-mechanical-chemical mechanisms responsible for early damage at the microscopic scale is required.

Project motivations:
To address the “oxidation-mechanical” coupling, HT-S4DefOx, a project funded by the European Research Council (ERC – Starting Grant), aims to:
– Evaluate mechanical behavior within the time-evolving gradient of microstructure and properties, i.e. within the “sub-surface” material (micro- and meso-scale approach);
– Evaluate the variability of the mechanical behavior of metallic materials in the vicinity of the metal/oxide interface (micro-scale approach). This interface, considered as the “extreme surface”, is at the forefront of thermo-mechanical-chemical coupling;
– Model and simulate thermo-mechanical-chemical coupling on microstructures and time-varying properties of the “sub-surface” material with boundary conditions on the “extreme surface”.

Problem and state of the art:
The aim of this research project is to design and develop a thermo-mechano-optical test bench dedicated to reproducing the thermo-mechano-chemical conditions of the oxidation mechanism representative of the in-service stresses studied, and to implement advanced instrumentation for observing this mechanism. The instrumentation will be based on coupled surface and subsurface, in-situ, kinematic, thermal and optical measurement methods, to analyze the thermo-mechano-chemical mechanisms of surface reactivity and local deformation at the microstructural scale for homogeneous materials, and even at the mesostructural scale for textured materials. Addressing this major technical challenge will enable us to study the “oxidation-mechanics” coupling in situ. The measurement methods targeted are high-resolution 2D and 3D digital image correlation (DIC) [8-10] and thermoreflectometry [11, 12], which offer the possibility of detecting and following the evolution of changes in the state of matter, and thus of studying the localization of deformation, temperature and optical properties of materials. In addition, the use of ultrathin samples for the study of surface reactivity has also shown strong potential for the study of chemical breakdown associated with the consumption of protective elements for the material at high temperatures [13, 14].

Objective and main stages of work:
The aim is to design and develop a prototype bench for kinematic, thermal and optical field measurements, combining digital image correlation and thermoreflectometry methods. These measurements are carried out at two scales: mesoscopic for the analysis of textured materials, and microscopic for the analysis of materials at the grain scale. Beyond the technical and technological challenge of this coupled measurement, the aim is to improve metrological understanding at these two scales, which are relevant to the study of deformation and surface reactivity of metallic materials at high temperatures.
In this work, the various mechanical, thermal and chemical aspects will be dissociated in order to initially study material deformation mechanisms independently of oxidation mechanisms on thin samples.

References:
1. Young DJ (2016) High temperature oxidation and corrosion of metals, 2nd Ed. Elsevier Science
2. Bensch M, Preußner J, Huttner R, et al (2010) Modelling and analysis of the oxidation influence on creep behaviour of thin-walled structures of the single-crystal nickel-base superalloy René N5 at 980C. Acta Mater 58:1607–1617.
3. Cassenti B, Staroselsky A (2009) The effect of thickness on the creep response of thin-wall single crystal components. Mater Sci Eng A 508:183–189. doi:10.1016/j.msea.2008.12.051
4. Finlay WL, Snyder JA (1950) Effects of three interstitial solutes (nitrogen, oxygen, and carbon) on the mechanical properties of high-purity, alpha titanium. JOM 2:277–286. doi:10.1007/BF03399001
5. Barkia B, Doquet V, Couzinié JP, et al (2015) In situ monitoring of the deformation mechanisms in titanium with different oxygen contents. Mater Sci Eng A 636:91–102. doi:10.1016/j.msea.2015.03.044
6. Pineau A, Antolovich SD (2009) High temperature fatigue of nickel-base superalloys – A review with special emphasis on deformation modes and oxidation. Eng Fail Anal 16:2668–2697. doi:10.1016/j.engfailanal.2009.01.010
7. Stinville JC, Echlin MP, Callahan PG, et al (2017) Measurement of strain localization resulting from monotonic and cyclic loading at 650 ∘C in nickel base superalloys. Exp Mech 57:1289–1309. doi:10.1007/s11340-017-0286-y
8. Stinville JC, Echlin MP, Texier D, et al (2016) Sub-grain scale digital image correlation by electron microscopy for polycrystalline materials during elastic and plastic deformation. Exp Mech 56:197–216. doi:10.1007/s11340-015-0083-4
9. Liu JH, Vanderesse N, Stinville JC, et al (2019) In-plane and out-of-plane deformation at the sub-grain scale in polycrystalline materials assessed by confocal microscopy. Acta Mater 169:260–274. doi:10.1016/j.actamat.2019.03.001
10. Charpagne MA, Hestroffer J, Polonsky AT, et al (2021) Slip localization in Inconel 718: a three-dimensional and statistical perspective. Acta Mater 215:117037. doi:10.1016/j.actamat.2021.117037
11. Sentenac T., Gilblas R., Bugarin F., Trichromatic thermoreflectometry for an improved accuracy of true temperature field measurement on a multi-material part, International Journal of Thermal Sciences, Elsevier, 145, p.art. 105980
12. Ecochard M., Pottier T., Texier D., Giblas R. et Sentenac T. , Early detection and in situ monitoring of the oxidation of a MCrAlY coating by thermoreflectometry, , 16th Quantitative InfraRed Thermography (QIRT) Conference, 2022, Paris.
13. Texier D, Ecochard M, Gheno T, et al (2021) Screening for Al2O3 failure in MCrAlY APS coatings using short-term oxidation at high temperature. Corros Sci 184:109334. doi:10.1016/j.corsci.2021.109334
14. Gheno T, Rio C, Ecochard M, Texier D (2021) Alumina failure and post-failure oxidation in the NiCoCrAlY alloy system at high temperature. Springer US

As part of this project, the engineer will:
– Design and develop a thermo-mechanical-optical bench for thermoreflectometry on mesoscopic and microscopic scales under thermal and thermomechanical loading;
– Design, develop and ensure synchronization of the kinematic, thermal and optical measurement chain;
– Design and develop the software for acquiring and processing the images collected;
– Calibrate the measurement chain and test bench;
– Carry out mechanical tests with image correlation and thermoreflectometry to track the location of deformation and the associated local temperature variation;
– Perform oxidation tests to initiate various oxidation events (chemical breakdown of the oxide, spalling, etc.) and measure associated optical property variations using InGaAs and CMOS sensor technology. Physico-chemical characterizations will document the chemical and topographical evolutions associated with these oxidation events.

Institut Clément Ader (ICA, CNRS UMR 5312).
The ICA is a research laboratory dedicated to the study of mechanical structures, systems and processes. Our areas of activity are in line with those of the mechanical industries, with a particular focus on projects in the aeronautics, space, transport and energy sectors. Our work generally focuses on behavioral modeling, instrumentation and durability studies for the structures or products under consideration. A major part of our research focuses on composite materials, which are now playing an increasingly important role in structures.

The ICA employs around 80 teaching and research staff, 20 temporary researchers, 20 administrative and support staff, 90 doctoral students and a large number of trainees. With the distinctive feature of having :
– on the supervisory level, staff from four major establishments: UPS and INSA from the Ministry of Higher Education and Research, ISAE from the Ministry of Defense, Mines Albi from the Ministry of Industry,
– geographically, with staff based in four towns in the Midi-Pyrénées region: Albi, Figeac, Tarbes and Toulouse.
The management team is made up of a director and two deputy directors, with the three supervisory ministries represented in this trio. The technical support team (BIATSS staff) is organized into three components, one for each ministry.

The laboratory is organized into four research groups:
– MSC Group: Composite Materials and Structures
– SUMO group: Surface, Machining, Materials and Tools
– MS2M Group: Modeling of Mechanical Systems and Microsystems
– MICS Group: Metrology, Identification, Control and Monitoring

This thesis work is in line with the research themes of the SUMO group, and more specifically the axis: Use properties and microstructures of advanced materials

The location of the thesis will be on :
INSTITUT CLEMENT ADER
IMT-Mines Albi-Carmaux
Campus Jarlard
81013 Albi CEDEX 09, France

The position is located in an area covered by the protection of scientific and technical potential (PPST), and therefore requires, in accordance with regulations, that your arrival be authorized by the competent MESR authority.

Requirements

Research Field

Engineering

Education Level

PhD or equivalent

Research Field

Physics

Education Level

PhD or equivalent

Languages

FRENCH

Level

Basic

Research Field

Engineering » Materials engineering

Years of Research Experience

None

Research Field

Physics » Acoustics

Years of Research Experience

None

Additional Information
Eligibility criteria

– Knowledge of Python programming language: instrument dialog-control, experimental data post-processing, image analysis
– Knowledge of optical properties of materials and optical assemblies
– Curiosity or desire to enter the world of research

Additional comments

This work is part of the ERC Starting Grant – HT-S4DefOx: High temperature – small scale sub-surface deformation assisted by oxidation. PhD requested

Website for additional job details

https://emploi.cnrs.fr/Offres/CDD/UMR5312-DAMTEX-016/Default.aspx

Work Location(s)

Number of offers available

1

Company/Institute

Institut Clément Ader

Country

France

City

ALBI

Geofield

Where to apply

Website

https://emploi.cnrs.fr/Candidat/Offre/UMR5312-DAMTEX-016/Candidater.aspx

Contact

City

ALBI

STATUS: EXPIRED