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Reference : UMR7182-MATLAU-003
Workplace : THIAIS
Date of publication : Thursday, October 31, 2019
Type of Contract : FTC Scientist
Contract Period : 15 months
Expected date of employment : 6 January 2020
Proportion of work : Full time
Remuneration : Around 2700 € gross / month depending on the experience (corresponding to around 2200 € net /month)
Desired level of education : PhD
Experience required : 1 to 4 years
The objective of this post-doctoral position is to establish a mechanical modelling of chemically architectured HEA and then, based on this modelling, to optimize their strength. Indeed, the microstructure of chemically architectured HEA depends on numerous characteristics, which cannot be all tested experimentally. At first, a mean field approach will be used based on the so-called “three phase model” (in which a coated inclusion is embedded in a matrix). The constitutive laws of the two phases and of the interphase will be identified from mechanical tests. Second, a full field approach based on the identification of a morphological model will be tested. Elastic-plastic constitutive laws, including crystal plasticity will be used for the behaviour of individual phases. The post-doc will be in charge of the modelling. He or she will also participate in the experimental mechanical testing of chemically architectured HEA, which will be processed and characterized by the other post-doc. Some results about mechanical testing of architectured HEA and modelling of single-phase HEA were already obtained by the teams involved in the project. They will serve as a starting point.
- Development of the mechanical modelling with several approaches.
- Performing mechanical testing
- Numerical optimization of mechanical properties
- Research in the scientific litterature
- Attending to the project meetings
- Presentations in national/international conferences. Writing of scientific papers.
- Co-supervising of master students.
- PhD in mechanics with a maximum of two years of experience after PhD
- The applicant should like modelling work as well as experimental one.
- Skills and knowledge in mechanical modelling by finite element method, especially applied to multi-phase materials, are needed. Having some expertise on homogenization methods and/or on full field approach is an advantage.
- Mastering the following techniques will be an advantage: Zset Finite Element code, compression and tensile tests.
- Additional skills: the applicant should be able to work within a project with several partners, to take initiatives, to write scientific papers. Speaking French will be a plus.
The Institute of Chemistry and Materials of Paris East (ICMPE) is an academic unit of research which depends on the CRNS and the Paris East University, in the field of chemistry and materials science. Multidisciplinary research activities revolve around four main areas: materials for energy, nano materials and scale effects, materials for the environment and sustainable development, and chemistry at the interface with health and living.
Scientific background and objectives
For many industrial applications as energy production, aeronautics or automotive sectors, materials are submitted to more and more severe environment. Thus, in order to obtain a breakthrough in properties, new families of alloys and new strategies of strengthening are needed. This project proposes fluctuations of chemical composition as a new strengthening mechanism in order to combine the functionalities of high mechanical strength, high ductility and high damage resistance. High entropy alloys (HEA) have been selected as good candidates to apply this new strengthening mechanism. HEA is a relatively new family of metallic alloys, which are multi-components and in which all components are very concentrated. In other words, the traditional distinction between major and minor elements is not relevant anymore for HEA. Applying the strengthening mechanism of composition fluctuations to HEA leads to a chemically architectured microstructure: (a) multi-component solid solutions at the nanoscale; (ii) grain boundaries at the submicron scale, (c) continuous composition gradients at the micron scale and (d) inter-connected network of the two phases and of the interphase at the mesoscale. The general objectives of the project are (i) to assess the efficiency of composition fluctuations as a new strengthening mechanism and (ii) to identify and optimize the microstructural parameters which control this strengthening mechanism.
This project is funded by a starting grant from the French National Agency for Research (ANR). The project coordinator of the project is Ms Mathilde Laurent-Brocq, from Institute of Chemistry and Materials of Paris East (ICMPE). Two teams of ICMPE as well as another one of the Material Center of Mines de Paris are involved. In addition with the permanent employees of those teams, two post-doctoral positions and one master internship will be funded by this project.
- Starting date: between January and March 2020
- Main location: ICMPE, Thiais France (South of Paris). Secondary location (around 1-2 days/month): Mines ParisTech Centre des Matériaux, Corbeil-Essonnes (South of Paris).
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