M/F Study of new architectured refractory complex concentrated alloys with eutectic microstructures

27 Mar 2024
Job Information

Organisation/Company

CNRS

Department

Institut de Chimie et des Matériaux Paris-Est

Research Field

Chemistry
Physics
Technology

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

16 Apr 2024 - 23:59 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

35

Offer Starting Date

1 Oct 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

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

No

Offer Description

The thesis will be hold at ICMPE (Thiais, 7 kms south from Paris) and IRCP (Paris, 5th district).

ICMPE is a research center in chemistry and material science and it covers a wide range of research areas, from design to the preparation and the optimization of materials in the frame of potential industrial applications (https://www.icmpe.cnrs.fr ). ICMPE (and more particularly the CAM's group: https://www.icmpe.cnrs.fr/recherche/departement-m2i/cam/ ) carries out in-depth multi-scale studies of new materials for structural and functional applications, mainly in the transportation and energy fields. It also has an extensive experience in the HEA field since they first studied RCCAs to prepare and develop high entropy alloys in 2012, leading to several publications and communications in the international community.

Among the new approaches to the design of metal alloys for structural or functional applications, that which aims to form concentrated solid solutions by mixing elements in equiatomic (or close to equiatomic) proportions is particularly attractive. Alloys resulting from this concept are often referred to as ”high mixing entropy” (HEA), and offer a wide spectrum of microstructures and properties (particularly mechanical), some of which are superior to conventional solutions. Among the avenues being explored, refractory HEAs (RHEAs) based on Hf, Ta, Ti, Nb, Mo, Zr, W, Cr or V are attractive, particularly in the aerospace industries, due to the stability of their specific mechanical properties, which are interesting up to 800-1000 °C, but drop sharply beyond that (from 0.6Tm, Tm being the melting temperature). However, applications such as aeronautical and hypersonic engines now require solutions that can withstand temperatures of up to 1400 °C, requiring a paradigm shift. Recently, a new approach has led to the design of carbon-rich RHEAs whose eutectic microstructure is composed of structurally simple carbides and a concentrated cubic-centered phase. The appeal of these architectured materials is twofold : eutectic microstructures are known for their high temperature stability, and their mechanical behavior is interface-driven.
The current project is part of the DoREMi ANR project (Development of New Advanced Refractory Concentrated Complex Alloys with Eutectic Carbide/BCC Microstructures ; 2024-2028), which aims to explore the potential of a new class of refractory complex alloys reinforced with eutectic carbides for structural applications under extreme temperature conditions (T>1200 °C). Four partners are directly involved in the project : ICMPE, IRCP, CEMES and LSPM. The proposed program is based on :
1. the development of a design strategy for ”simplified” eutectic alloys (3 to 4 elements maximum, mostly refractory and including carbon) using predictive thermodynamic tools (Calphad method, basic Python programming).
2. the preparation of bulk materials in the form of small ingots by electric arc ; perform crystal growth to control eutectic phases.
3. the fine characterization of the prepared microstructures with XRD, SEM, DSC/r´esistivity, TEM. A
particular attention will be drawn on carbide/cubic phase interfaces whose temperature stability is crucial for the macroscopic behavior. In such framework, visits at CEMES will be encouraged.
4. the assessment of mechanical properties for the selected compositions at LSPM.

The ambitious nature of the PhD proposal lies in the chosen approach and focuses around scientific axes considered as expertise domain of the two hosting research groups (ICMPE - CAM's group & IRCP - MS' group). More particularly, alloy preparation will be performed with the arc melting technique and microstructure characterization will done with tools that are considered (DRX, resistivity, SEM, TEM...). Mechanical properties of the selected alloys will be assessed with simple tests (compression mainly). Deformation mechanisms will be finely analyzed by SEM and TEM in collaboration with all the partners involved in the projet.

The candidate should own a strong background in materials science and more particularly in metallurgy.

Requirements

Research Field

Chemistry

Education Level

Master Degree or equivalent

Research Field

Physics

Education Level

Master Degree or equivalent

Research Field

Technology

Education Level

Master Degree or equivalent

Languages

FRENCH

Level

Basic

Research Field

Chemistry

Years of Research Experience

1 - 4

Research Field

Physics

Years of Research Experience

1 - 4

Research Field

Technology

Years of Research Experience

1 - 4

Additional Information
Additional comments

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

Website for additional job details

https://emploi.cnrs.fr/Offres/Doctorant/UMR7182-JEACOU-001/Default.aspx

Work Location(s)

Number of offers available

1

Company/Institute

Institut de Chimie et des Matériaux Paris-Est

Country

France

City

THIAIS

Geofield

Where to apply

Website

https://emploi.cnrs.fr/Candidat/Offre/UMR7182-JEACOU-001/Candidater.aspx

Contact

City

THIAIS

STATUS: EXPIRED