Closed-loop process control for electron beam freeform fabrication and deposition processes

A closed-loop control method for an electron beam freeform fabrication (EBF3) wherein, using an EBF3 apparatus, a wire is melted via an electron beam in a vacuum chamber and progressively deposited as a molten pool, the molten pool being cooled in layers on a substrate, the method comprising:

• collecting images of a feature of interest of the molten pool during the EBF3 process using at least one camera positioned inside of the vacuum chamber;
• continuously evaluating the images using a host machine to determine, in real time, a magnitude and a rate of change occurring in the feature of interest, including at least a height of the molten pool;
• and
• automatically modifying a set of control parameters to the EBF3 apparatus, via the host machine, in a closed-loop manner to thereby control the EBF3 process.

An apparatus for providing closed-loop control method of an electron beam freeform fabrication (EBF3) process, wherein a wire is melted via an electron beam and progressively deposited onto a substrate as a molten pool, and wherein the molten pool is cooled in layers on the substrate, the apparatus comprising:

• a vacuum chamber;
• an electron gun positioned in the vacuum chamber and adapted for generating the electron beam;
• a wire feeder adapted for feeding the wire toward a substrate;
• a main process controller adapted to control the electron gun and the wire feeder via a set of control parameters, wherein the wire is melted into a molten pool and progressively deposited in layers onto the substrate to form a product;
• at least one sensor adapted for measuring a feature of interest of the molten pool during the EBF3 process, wherein the feature of interest includes at least one of a height of the molten pool, a distance between the molten pool and the wire feeder, and a temperature of at least one of the layers;
• and
• a host machine having an algorithm for continuously evaluating the feature of interest to determine, in real time, a change occurring therein;
• wherein the host machine is configured to execute the algorithm and thereby automatically generate a set of input parameters that modifies the set of control parameters, thereby controlling the EBF3 process in a closed-loop manner.