C. J. Li, G. J. Yang, C. X. Li, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, China; H. Bang, H. Bang, Department of Naval Architecture and Ocean Engineering, Chosun University, Gwangju, South Korea; W. Y. Li, Northwestern Polytechnical University,, Xi'an, China
The critical velocity is a key parameter in cold spraying. The appropriate estimation of the critical velocity benefits the optimization of coating deposition in terms of deposition efficiency. The critical velocity can be estimated experimentally through measuring the relation between deposition efficiency and particle velocity. The recent study has revealed that the critical velocity can be estimated by the velocity resulting in the onset of adiabatic shear instability through numerical simulation of particle impact. However, it was found that the critical velocities of a pure metal material obtained by different investigators through simulation were significantly different. No reasonable explanation was provided to such difference. In the present paper, the critical velocities reported in the literature for copper as a typical material were reviewed. The factors influencing the critical velocity are examined. The numerical simulation methods employed in the limited literature are examined to better understanding of the factors which influence the simulated results. The reasonable estimation method is proposed of the critical velocity using the numerical critical velocity.
Summary: The critical velocity is a key parameter in cold spraying. The appropriate estimation of the critical velocity benefits the optimization of coating deposition in terms of deposition efficiency. The critical velocity can be estimated experimentally through measuring the relation between deposition efficiency and particle velocity. The recent study has revealed that the critical velocity can be estimated by the velocity resulting in the onset of adiabatic shear instability through numerical simulation of particle impact. However, it was found that the critical velocities of a pure metal material obtained by different investigators through simulation were significantly different. No reasonable explanation was provided to such difference. In the present paper, the critical velocities reported in the literature for copper as a typical material were reviewed. The factors influencing the critical velocity are examined. The numerical simulation methods employed in the limited literature are examined to better understanding of the factors which influence the simulated results. The reasonable estimation method is proposed of the critical velocity using the numerical critical velocity.
