- Head of the Surface Treatments and Corrosion entity

  CNAM Laboratory of Metal and Polymer Industrial Materials (EPN 04)

- Responsible for Glow Discharge Spectrometry (GDS), advanced technique for surface analysis of solid materials

  Processes and Mechanical and Materials Engineering Laboratory (PIMM)

Ongoing research projects

- ANR COQTEL propject : COrrosion Quantification Through Extended use of Lamb waves

   PIMM members : Marc Rebillat, Nazih Mechbal, Sébastien Dubent

In the framework of the transition toward condition-based maintenance, connected objects deployment is reinventing monitoring processes. This is extremely relevant with respect to corrosion which represents a significant issue in aeronautics. In 2016 the annual corrosion cost for commercial aircraft fleet operated by European airlines was estimated to 2.2 B$. Anticipating corrosive conditions ahead of time is estimated to generate between 15% and 35% of cost savings. Specific coatings are used to prevent corrosion but remain limited in their ability to completely avoid structural corrosion specially in harsh operational environment. To detect such damages, nondestructive testing methodologies for corrosion consist in “on ground” regular visual inspection which does not allow detection of the corrosion damage premises, precise quantification of corrosion damage size, and prediction of the remaining useful life of associated parts. Adding on board native connectivity to aircraft metallic parts appears as the key technology to safely face this issue while minimizing costs and environmental impact. This goes through embedding ultrasonic sensors into aeronautic airframe parts and providing them with on board structural health monitoring algorithms and digital twins able to improve operational availability without compromising safety. COQTEL is the joint multidisciplinary effort of French experts in structural health monitoring (PIMM lab), ultrasonic hardware designing (CTEC SME), aerospace metallic parts coating (RESCOLL SME), and corrosion and fatigue modelling (I2M lab) to face this challenge. It proposes to move from classical “on ground” non-destructive testing to “on board” condition-based maintenance by embedding ultrasonic sensors in aircraft metallic parts and by developing and validating dedicated hardware, digital twins, and algorithms endowing airframe parts with built-in corrosion monitoring functionalities. The ambition of COQTEL is to detect the premises of corrosion, to quantify the size of in situ corrosion damages, and to be able to predict associated remaining useful life in order to participate in the revival of the aeronautical industry and the SMEs accompanying it by providing them with a proof of concept of the use of intelligent aeronautical structures for predictive maintenance.

Direct links : https://twitter.com/CoqtelP ; https://www.linkedin.com/in/coqtel-project-915b48209/?originalSubdomain=fr ; https://anr.fr/Project-ANR-20-CE42-0014

- CompoFus project : Direct metal deposition (DML) development and characterization of Fe-TiB2 metal matrix composites

   PIMM members : Sébastien Dubent, Zehoua Hamouche, Cyril Gorny

In the current economic and social context (increase in the cost of fossil fuels, reduction of CO2 emissions, energy transition, etc.), the introduction of Fe-TiB2 composite steels in the automotive and transport sector in general, for stiffness-dimensioned parts (engine cradle, suspension arms, etc.), would allow a significant lightening of 15 to 30% of the mass of vehicles. It is therefore of major interest to answer the question of the technical possibility of producing such Fe-TiB2 composite steels by the direct metal deposition (DML) process.

Skills

- Expertise in corrosion of metallic materials

- Research experience in conducting corrosion tests

- Mastery of the main electrochemical methods of corrosion analysis

- Control of metal surface treatment processes: coatings and treatments

- Expertise in Glow Discharge Spectrometry (GDS)

- Skills in surface characterization and thin film analysis

- Scientific Instrumentation Skills

- Skills in characterization of metallic materials

- Competent Person in Radiation Protection

Knowledge

- Material Sciences

- Structure, properties and characterization of metallic materials

- Surface treatment of metals

- Electrochemical methods of corrosion analysis

- Corrosion of metallic materials

- Thin film characterization and analysis techniques

- Glow Discharge Spectrometry (GDS)

- Higher education and public research

Main publications

- Caractérisation des revêtements et traitements de surface par SDL

  S. Dubent, Traitements & Matériaux, 464, (2020)

- Application of an experimental design to study AISI 4340 and 300M steels electropolishing in a concentrated perchloric / acetic acid solution

  V. Roscol, S. Dubent, W. Bensalah, S. Mierzejewski, R. Ottenio, M. DePetris-Wery, H. F. Ayedi,

  Engineering Research Express, 2(3), 035007, (2020)

  https://iopscience.iop.org/article/10.1088/2631-8695/ab9963

- Characterization and corrosion behaviour of titanium used in electrolysers for hydrogen production

  S. Dubent, A. Mazard, Int. Journal of Hydrogen Energy Vol. 44, Issue 297, 15622-15633 (2019)

- Caractérisation des surfaces par SDL

   S. Dubent, P. Chapon, Editions des Techniques de l’Ingénieur, M1675v3 (2017)

- Electrodeposition, characterization and corrosion behaviour of tin-20 wt.% zinc coatings

  electroplated from a non-cyanide alkaline bath, S. Dubent, M. L.A.D. Mertens, M. Saurat,

  Materials Chemistry and Physics, Vol. 120, Issues 2-3, 371-380 (2010)

- Mise au point et optimisation d’un alliage étain-zinc électrodéposé en remplacement du revêtement

  de cadmium, S. Dubent, M. Saurat,

  Bulletin du cercle d’Études des Métaux, SURMAT 08, Traitements de conversion sur aciers zingués et

  alliages légers, quelles conséquences pour l’atelier de demain, Tome XVIII N° 1 (2009)

- Revêtement d’alliage étain-zinc, électrodéposé dans un bain alcalin non cyanuré,

  S. Dubent, M. Saurat, Galvano Organo Trait. de Surface & Peinture, N° 776, 54-57 (2008)

- Composition control of tin–zinc electrodeposits through means of experimental strategies,

   S. Dubent, M. De Petris-Wery, M. Saurat and H.F. Ayedi,

   Materials Chemistry and Physics, Vol. 104, Issue 1, 146-152 (2007)

- Mise au point et optimisation d’un alliage étain-zinc électrodéposé en remplacement du revêtement

  de cadmium, S. Dubent, Mémoire d’ingénieur du Conservatoire National des Arts et Métiers (2007)

- Analysis of chemical nickel coatings by luminescent discharge spectrometry,

  S. Dubent, M. Saurat, Galvano Organo Trait. de Surface, N° 721, 329-332 (2002)