This paper provides an overview of two particle imaging techniques that have proven useful in the development and implementation of thermal spraying processes. It covers the basics of each method, including the hardware setup, the interpretation of output data, and example applications. Paper includes a German-language abstract.

This paper describes a powerful new approach, based on optical emission spectroscopy, for monitoring thermal spraying processes and coating quality. Through online analysis of the emitted process spectra, users can track variations in the running process as well as in the coatings produced. As proven in numerous studies, all relevant process parameters can be separated and detected using OES techniques, and recent work indicates that the method is applicable to all thermal spray processes. Paper text in German.

The University of Limoges developed a compact sensing module that measures particle beam properties and substrate surface temperatures during plasma spraying. In this paper, the authors explain how they built and tested a closed-loop controller for APS processes using the sensing module. One of the key elements in the online control system is an empirical model that relates process inputs, in-flight particle parameters, substrate temperatures, and coating properties. The paper discusses the development and implementation of the model and the determination of the main input parameters. Paper includes a German-language abstract.

This paper provides an overview of the tools and techniques used in industry to monitor and control plasma spraying processes. It describes how the tools work and what they can reveal about spraying processes and coating properties. It also presents examples showing how the tools are used to optimize spray parameters for special applications and discusses the possibility of implementing closed loop control for plasma spraying processes. Paper includes a German-language abstract.

This work evaluates the capabilities of a digital camera selected for use in a thermal spray diagnostic system. The CCD-based image sensor, a Sony Exview HAD, was tested in an industrial plasma-spraying process and is assessed in terms of the information it provides about the plasma jet, particle-substrate interactions, and coating growth. Zirconium dioxide and aluminum oxide ceramics are examined as typical powder systems. Paper includes a German-language abstract.