Missions

The postdoc will develop 3D-printed ultrarefractory ceramics parts using DIW and SLA, combined with conventional and SPS sintering. The goal is to minimize sintering additives while preserving high densification and the high-temperature performance.

Activités

This postdoctoral project focuses on the fabrication of complex-shaped zirconium diboride (ZrB₂) components in 3D. ZrB₂ serves as a model system for studying the control of high-temperature sintering. The project combines two complementary sintering approaches: conventional sintering with a high proportion of additives (~5%) and spark plasma sintering (SPS) with a very low additive content (less than 1%). ZrB₂ is a classical ultra-high-temperature ceramic (melting point above 3000 °C), but its processing is challenging due to the need for significant amounts of additives such as B₄C and carbon in conventional sintering. The goal of the project is to optimize these processes to produce high-performance ZrB₂ components while minimizing additives, thereby preserving the excellent high-temperature properties of the material.
The first approach (Axe 1) involves using robocasting (DIW) to print ZrB₂ parts with a higher additive content, followed by conventional high-temperature sintering. This method aims to enable the printing of larger and thicker self-supporting components, which remains a major challenge in the current literature, typically limited to small parts.
The second approach (Axe 2) uses DIW-printed and pre-sintered parts, along with stereolithography (SLA) to print graphite "sub-molds" that define interfaces. These sub-molds are then used to assemble and sinter ZrB₂ with a low additive content using SPS. This technique combines the geometric precision of SLA for fabricating complex mold networks with the efficiency of SPS to achieve fine-grained microstructures, minimal additive content, and outstanding high-temperature properties. By coupling 3D printing with sintering, these two strategies aim to advance the fabrication of ZrB₂ ceramics, enabling the production of complex and high-performance components for extreme applications.

Compétences

The following skills are highly recommended:
- 3D printing,
- Suspensions formulation,
- Rheology,
- Zetapotential,
- Sintering,
- Nnumerical skills,
- Scientific article writing.

Contexte de travail

The postdoctoral researcher will primarily carry out work involving synthesis, formulation, and fundamental analysis of the sintering mechanisms involved. The results will be disseminated exclusively through scientific publications, as the technologies have already been patented. The objective is to demonstrate that the sintering of parts by SPS can be extended to even higher temperatures.
This post-doctoral contract will be carried out within the CRISMAT laboratory (a joint CNRS, ENSICAEN and Caen Normandy University research unit), which has around 100 members, in the 'Materials and Processes' team, under the responsibility of Charles Manière (CNRS Research Fellow).

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

This job offer is subject to funding and applications are submitted to the Human Resources department for consideration.