Thermal characteristics such as process temperatures and melt pool sizes offer important information in metal additive manufacturing (AM) technologies such as powder-bed electron beam additive manufacturing (EBAM). In this study, a near infrared (NIR) thermal imager was employed to acquire build surface process temperatures during EBAM fabrications using Ti-6Al-4V powder. Challenges in NIR temperature measurements for EBAM were tackled including compensating temperatures due to the transmission loss and estimating the emissivity of Ti-6Al-4V in its molten state. At a beam speed of about 728 mm/s, a beam current of about 7.2 mA and a diameter of 0.55 mm, the maximum process temperature is on the order of around 2700 °C, and the melt pools have dimensions of about 2.72 mm and 0.72 mm in length and width, respectively.

This content is only available via PDF.
You do not currently have access to this content.