Infrared radiation sensing and beam control in electron beam additive manufacturing

Abstract

Apparatuses for dynamically sensing infrared (IR) radiation in an electron beam powder bed fusion (EB-PBF) printer are provided. A radiation collector receives radiation from a surface of the powder bed. An IR-transparent material rejects one or more non-IR wavelengths, and a lens focuses the IR radiation onto an optical fiber. The IR radiation is carried from the vacuum chamber of the printer to a sensor, where IR information is determined based on the received IR radiation. The IR information may be received from the sensor and used by the print controller to modify one or more parameters, such as beam intensity or scanning rate, on the fly or during the next print cycle. An occlusion member can be used to selectively block or expose the radiation collector to protect the radiation collector from condensation of vapor from vaporization of particles at high temperatures.