Journal
JOURNAL OF THERMAL SPRAY TECHNOLOGY
Volume 26, Issue 3, Pages 327-339Publisher
SPRINGER
DOI: 10.1007/s11666-016-0516-3
Keywords
critical velocity; deposition mechanism; fracture mode transition; shock wave; vacuum kinetic spraying (VKS) process
Categories
Funding
- National Research Foundation of Korea (NRF) - Korean government (MEST) [NRF-2014R1A2A2A05007633]
Ask authors/readers for more resources
Vacuum kinetic spraying (VKS) is a promising room-temperature process to fabricate dense ceramic films. However, unfortunately, the deposition mechanism is still not clearly understood. In this respect, the critical conditions for successful deposition were investigated. Based on simulation and microstructural analysis, it was found that as the particle velocity increased, fracture mode transition from tensile fracture to shear fracture occurred and particle did not bounce off anymore above a certain velocity. Simultaneously, particle underwent shock-induced plasticity and dynamic fragmentation. The plasticity assisted to prevent the fragments from rebounding by spending the excessive kinetic energy and fragmentation is essential for fragment bonding and film growth considering that the deposition rate increased as the fraction of fragmentation increased. Accordingly, plasticity and fragmentation take a crucial role for particle deposition. In this respect, the velocity that fracture mode transition occurs is newly defined as critical velocity. Consequently, for successful deposition, the particle should at least exceed the critical velocity and thus it is very crucial for film fabrication in VKS process at room temperature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available