In the thermal spray process, particle state at impact is among the key factors influencing the quality, characteristics and properties of the deposit formed. Measuring and eventually controlling in-flight particle jet characteristics can help ensure the repeatability of desired coating properties. Moreover, monitoring particle jet can lead to cost savings by allowing replacement of consumable parts on a need-basis rather than on a preventive basis. However, successful use of in-flight particle sensors in a production environment requires developing an implementation strategy that minimizes impact on coating cycle time, limits operator intervention and reduces analysis time, while still generating useful data. The usefulness of in-flight particle sensor in a high yield production environment is investigated. A preliminary study was first conducted to define a strategy to implement the data acquisition process using an ensemble in-flight particle monitoring system that allows real-time measurements of average particle temperature and velocity and overall particle jet profile. Data was collected to capture representative torch and particle jet behaviors over the life of several consumable hardware sets. Evolution of the particle jet parameters over time is compared to that of some of the process parameters, as well as to the deposition efficiency and one selected characteristic of the coating deposited. Some trends are identified, and potential benefits and drawbacks of using in-flight particle monitoring in a high yield production environment are highlighted.
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