ONLINE MONITORING OF THE ELECTRIC ARC-SPRAYING PROCESS-BASED ON ACOUSTIC SIGNATURES

Electric are spraying (or metal are spraying) is a process that deposi ts metal particles on suitable substrates using two consumable wire el ectrodes. The high-temperature are formed between these electrodes in an atomizing jet of air produces small molten particles which are used to coat the substrate. The contribution of the process parameters and their interactions on the coating thickness is analysed using Taguchi 's design of experiments. The time and frequency domain sound signals generated during the process are utilized to characterize the spraying phenomenon. Stochastic modelling of acoustic signals forms the basis for a closed-loop control mechanism of the are-spraying process propos ed for the first time. Experimental proof of the Gaussian nature of th e deposition profile is provided and a mathematical approach has been suggested to obtain a uniform deposit thickness in a single pass.