Abstract No.:

 Scheduled at:
Thursday, May 05, 2022, Hall G1 2:00 PM
Modeling & Simulation III

A physics based model for ultrahigh strain rates in cold spray

Sabeur Msolli* / UTBM, France
Zhi-Qian Zhang / Institute for High Performance Computing, A*STAR, Singapore 138632 , Singapore
Rija Raoelison/ ICB UMR 6303, CNRS, Université Bourgogne Franche-Comté, UTBM, F-90010 Belfort, France, France

Cold Spray technology keeps attracting several industries in both the manufacturing and repair sectors, thanks to its practicability and its reasonable processing time. Moreover, different kinds of materials can be successfully deposited to form coatings with potential excellent thermoelectromechanical properties. The coating microstructure is completely different from that produced by wrought powder material before the deposition process. In case of metallic materials, the thermomechanical characteristics are quite dependent on the deposition conditions (gas temperature, impact velocity and angle, material combination, surface state, particles size, etc). Hence, one major factor that influences the final coating microstructural state is the kinetic energy. In fact, in such processes where high velocity deposition is observed, both intense grain refinement and sharp increase of dislocation density are an outcome that is tightly related to the high temperature and the severe plastic deformation. Prediction of the mechanical properties of the coating is usually carried out using phenomenological models that describe very well the relationship between stress and strain under different conditions of temperature and strain rates. Most of these models fail, however, to describe the effect of the deformation mechanisms observed at ultra high strain rates such as the viscous drag regime of dislocations or further the weak shock load regime, scenarios commonly observed in such processes. In the present paper, we present an enhanced physics based model to describe the stress strengthening of metals upon impact and associated microstructure changes. We show that the model can accurately represent the desired effect of the dislocation drag. Modeling of the impact of a single copper particle onto a copper substrate is carried out to show the capability of the model to predict grain refinement and dislocation network modification

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