Method for identifying in flight particles based on digital image technologies in thermal spraying

In thermal spray process, the characteristics of in flight particles (velocity and temperature) play an important role regarding the microstructure of the deposit and thus the coating performances. The implementation of diagnostic devices is necessary to measure such characteristics. Many imaging systems and algorithms have been developed for identifying and tracking in-flight particles. However, these current image systems have significant limitations. One key to solve the tracking problem is to get an algorithm that can effectively identify different particles at the same time in a same image frame. The aim of this study is to develop an algorithm capable of identifying a mass of flying particles sprayed by thermal process. Results show that noise and shadows could be successfully treated, particles are clearly recognized in the background leading to measure properly the sizes and the positions of the particle versus time.

 

Keywords: in-flight particle behavior, images treatment, noise reduction, object identification, in-flight particle diagnostics