Evaluations of Temperature Measurements by Near-infrared Thermography in Powder-based Electron-beam Additive Manufacturing

Powder-based electron beam additive manufacturing (EBAM) has gained increased usage in different industries. Process monitoring such as temperatures may offer important information. However, temperature measurements in EBAM are challenging because of high temperature ranges, extreme gradients and fast transient response. In this study, temperature measurements during the EBAM process, in particular, around the electron beam scanning area, were attempted using a near-infrared thermal camera. The obtained temperature data demonstrated the feasibility of such a measuring technique. The thermal camera was able to capture the pre-heating, contour melting, and hatch melting events. Further, the achievable spatial resolution is around 12 μm when using a 350 mm lens.