Abstract
Up to now, the role of particle sizes on the impact behavior of ceramic particles in aerosol deposition not yet fully understood. Hence, with the aim to supply a more general understanding, modeling series of low strain rate compression and high-speed impact were performed by molecular dynamics on single-crystalline particles in sizes of 10-300 nm that are tuned to match mechanical properties of TiO2-anatase. The modeling results reveal that particles with original diameter of 25-75 nm exhibit three different impact behaviors that could be distinguished as (i) rebounding, (ii) bonding and (iii) fragmentation, depending on their initial impact velocity. In contrast, particles larger than 75 nm do not exhibit the bonding behavior. Detailed stress and strain field distributions reveal that combination of “localized inelastic deformation” along the slip systems and “shear localization” cause bonding of the small and large particles to the substrate. The analyses of associated temperature rise by the inelastic deformation revealed that heat diffusion at these small scales depend on size. Whereas small particles could reach a rather homogeneous temperature distribution, the evolved heat in the larger ones keeps rather localized to areas of highest deformation and may support deformation and the formation of dense layers in aerosol deposition.
Highlights
Aerosol deposition (AD) is a room-temperature spraying technique for producing ceramic films on a variety of substrate materials, including metals, ceramics and evenJ Therm Spray Tech (2021) 30:503–522 polymers (Ref [1,2,3,4,5])
The particles were all compressed up to 20% of their initial diameters and unloaded
The Von Mises atomic shear strain field is a useful criterion in atomic simulations showing local regions where inelastic deformation occurs
Summary
J Therm Spray Tech (2021) 30:503–522 polymers (Ref [1,2,3,4,5]) By this method, submicron to micron size ceramic particles (Ref 1-5) are accelerated to velocities of typically [100-550] m/s by a gas flow through a converging nozzle and expansion into a vacuum chamber, where they impact onto the substrate (Ref [1,2,3,4,5]). Associated models should address open questions concerning the roles of (i) ceramic particle sizes, (ii) their impact velocities and (iii) the observed nano-crystallization in deposited layers (Ref [1,2,3]).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
