Frontier Research Institute for Interdisciplinary Sciences
Tohoku University


Chrystelle BERNARD

Assistant ProfessorDevice Technology

Mentor Information
Associate Professor
Kazuhiro Ogawa(Graduate School of Engineering)
Research Fields Dynamics behavior of polymers, cold-spray
Research Subjects
  • Thermomechanical behavior of polymers during cold-spray process
  • Understanding of the adhesion mechanisms occurring during cold-spray process
Academic Society Membership Mechanical French Association
Research Outline  

Cold-spray (CS) process is an interesting technology which allows welding different materials to form a layer protecting structure. It consists in projecting at high speed, against a substrate, powdered materials through a nozzle using a pressurized gas. Relative good understanding of CS was achieved for metallic powders and substrates. Since few years, some researches [1,2,3] have been focused on cold-spraying polymer particles. Contrary to metals, polymers exhibit high sensitivity to strain rate and temperature. Using an empirical approach, the addition of nanoalumina particles allowed obtaining thick and porous coatings. However, the role of these particles on the adhesion mechanisms during CS process is still unknown.

My research aims to improve CS process through a better understanding of the formation and growth of the polymer coating. These steps depend on the balance between kinetics, rebound and adhesion energies. This requires the knowledge of the polymer behavior law, at ultra-high strain rate and strong temperature gradient, and its implementation in finite element software to simulate CS process.

[1] Development of Ultra-High Molecular Weight Polyethylene (UHMWPE) Coating by Cold Spray Technique, Journal of Thermal Spray Technology, 24 (6), 1015-1025, 2015.

[2] Mechanistic Study and Characterization of Cold-Sprayed Ultra-High Molecular Weight Polyethylene-Nano-ceramic Composite Coating, Journal of Thermal Spray Technology, 25 (1-2), 160-169, 2016.

[3] International Patent US 20170152601 A1

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