Temperature monitoring of the molten bath in electron beam additive manufacturing using spectral thermography

This article presents a spectral thermography method for monitoring the spatial temperature distribution in the molten bath during additive manufacturing of metal parts, along with the experimental setup designed to implement this method. The approach is based on multispectral imaging across four narrow-band spectral channels using a single image sensor. The method was experimentally tested on an electron beam additive manufacturing system. The raw experimental data exhibited characteristic distortions caused by partial material deposition on the protective camera window. A dedicated preprocessing algorithm was developed to compensate for these distortions. Experimental results from electron beam additive manufacturing system demonstrate the feasibility of detecting relative temperature changes during the additive synthesis process. At the selected frame capture rate, periodic temperature fluctuations are observable in the spatial temperature maps, correlating with the specific cladding mode parameters. The overall pattern of the spatial temperature distribution in the mol - ten bath shows a high degree of consistency with theoretical predictions reported in earlier publications. These findings confirm the potential for further application of the proposed approach in temperature regime monitoring during additive manufacturing processes.

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