Laser Absorptivity Measuring Device

A compact, high-throughput diagnostic tool for characterizing laser-based processes

Characterizing the laser absorptivity and efficiency compensation of laser-based processes can provide useful avenues for defect characterization and mitigation; however, laser-metal interactions during welding and metal additive manufacturing are notoriously complex. Existing techniques for measuring laser absorption efficiency rely on reflective rather than direct measurements, require the use of simulative samples that add assumptions, and/or involve large processing setups that behave differently than the genuine process.

Researchers at Sandia National Laboratories have invented a compact diagnostic tool for directly measuring the absorptivity of laser-based processes such as powder bed fusion additive manufacturing and welding. The device’s small integrating hemisphere with a reflective baseplate can be placed on top of any processing substrate directly inside the equipment and can measure reflections of a moving heat source. An optical diode ensures capture of all back-reflected light. By correlating transience with defect formation, this device can lead to enhanced performance, properties, and defect mitigation through improved process monitoring and control.