System and method for monitoring and controlling build quality during electron beam manufacturing

A system for adaptively forming a three-dimensional build part from a plurality of deposited layers of metallic powder, said system comprising:

• a build chamber comprising:
• a housing;
• a build platform disposed in the build chamber;
• and
• an actuator for moving the build platform in the build chamber;
• at least one electron beam source for directing at least one electron beam into the build chamber and onto the plurality of deposited layers of metallic powder disposed on the build platform to form a melt pool;
• an energy sensitive photon-counting detector that includes one or more of energy and wavelength dispersive components, the energy sensitive photon-counting detector configured to detect in real-time backscattered energy ejected from the melt pool being exposed to the at least one electron beam to detect a defect in the melt pool, the backscattered energy being one or more of backscattered electrons, secondary electrons, Auger electrons, backscattered photons, and radiation ejected from the melt pool and the defect indicative of a defect in at least one of a density and a chemistry of the three-dimensional build part, the energy sensitive photon-counting detector configured to generate a detection signal representative of the defect;
• a processor configured to receive and analyze the detection signal and generate a corrective signal;
• and
• a controller configured to receive the corrective signal and provide control of at least one of the actuator and the at least one electron beam source to direct the at least one electron beam onto the plurality of deposited layers of metallic powder on the build platform to sequentially consolidate patterned portions of the plurality of deposited layers of metallic powder to adaptively form the three-dimensional build part;
• wherein each the actuator and the at least one electron beam source is configured for adjustment by the controller based on the corrective signal, and the adjustment by the controller affects at least one of a consolidation rate and a melt pool size.

A method for monitoring and controlling build quality during electron beam manufacturing of a three-dimensional build part, the method comprising:

• (a) providing at least one electron beam source;
• (b) controlling the at least one electron beam source to direct an at least one electron beam onto a deposited layer of metallic powder to form a melt pool;
• (c) detecting backscattered energy from the melt pool with an energy sensitive photon-counting detector in real-time to determine a presence of a defect in the melt pool, wherein the defect is indicative of a defect in at least one of a density and a chemistry of the three-dimensional build part, wherein the energy sensitive photon-counting detector includes one or more of energy and wavelength dispersive components;
• (d) controlling at least one of the electron beam source and an actuator to adjust the at least one electron beam and a build plate in response to the determined presence of the defect in the melt pool and consolidate patterned portions of the deposited layer of metallic powder, wherein each the actuator and the at least one electron beam source is configured for adjustment based on the defect in the melt pool, and the adjustment affects at least one of a consolidation rate and a melt pool size;
• and
• (e) repeating (a)-(d) to form the three-dimensional build part.