System and method for in-situ characterization and inspection of additive manufacturing deposits using transient infrared thermography

An additive manufacturing system, comprising:

• a deposition head comprising:
• a heat source;
• a wire feeder;
• and
• one or more thermal imagers configured to sequentially in time capture thermal images of deposition of feed material heated by the heat source to form a structure layer by layer;
• and
• a processor connected to the one or more thermal imagers, wherein the processor is configured to:
• reconstruct thermal images from the sequentially in time captured thermal images, wherein reconstructing the thermal images comprises combining a number of the sequentially in time captured thermal images of the deposition for a given time period by pixel point location in the sequentially in time captured thermal images such that the reconstructed thermal images represent the deposition's transient temperature response spatially across all the in line pixel points and temporally at each respective pixel point for the given time period;
• process the reconstructed thermal images to detect a defect in the structure based on the transient temperature response of at least one of the in line pixel points in the reconstructed thermal images;
• and
• adjust deposition of the feedstock or adjust the heat source in response to detecting the defect.