Plasma jet imaging by CCD technology in rapid mold manufacturing

Plasma spraying, as an important enabling technology, is being applied to rapid mould manufacturing in order to reduce the development time and manufacturing cost. Due to the melting and in-flight states of powders being affected directly by the plasma jet, which ultimately determines the quality of the bulk deposit, there is an increasing interest in research on the diagnostics and control of plasma spray processing. This paper presents a compact, low-cost and practical method for the real-time diagnosis of a plasma jet, which integrates CCD and computer imaging technology. The collecting principle and methods were especially investigated, whilst the fake color processing of the jet image and jet shape under different process parameters were studied also, using an experimental system of real-time data collection by the present method. The current work is of paramount importance for further study of the closed-loop control of plasma spraying processes, which could turn plasma digitized manufacturing into reality.