We have intensely explored various facets of the Laser Powder Bed Fusion (LPBF) process, a pivotal technique in additive manufacturing, also known as Selective Laser Melting. Our central focus has been on in-situ characterization and real-time monitoring using state-of-the-art technology including Long-Wave Infrared (LWIR) and Short-Wave Infrared (SWIR) cameras to garner detailed insights into the thermal dynamics during the LPBF process.
One of the defining features of our research is leveraging the LWIR camera to monitor and analyze the thermal history of the powder layer immediately post the deposition by the recoating system, facilitated through thermographic inspection. This enabled a comprehensive understanding of how thermal properties and powder layer thickness correlate, eventually providing a path to predict part distortions precociously before severe distortions occur, aiming to prevent catastrophic recoater crashes and to foster in-situ monitoring of the powder layer properties.
Meanwhile, employing SWIR cameras opened avenues to understand the intricate relationship between thermal histories, detected through in-situ observations, and their consequential effects on part properties, including the development of thermal feature-based porosity probability maps. Moreover, we delved deep into the impacts of varied laser processing parameters and complex scan pathing on the thermal features, correlating them effectively with the part’s engineering properties.
We have also acknowledged the critical role played by feedstock variations and changes in powder characteristics with reuse, emphasizing a meticulous analysis of the underlying factors that foster inconsistencies in part properties. Our collective endeavors lay a robust foundation for in-situ part qualification, heralding a future where the LPBF process is both safe and more efficient, with enhanced quality control measures in place.
We warmly invite you to collaborate with our team as we spearhead further studies in this LPBF domain.
Recent Publications
2023
Liu, Tao, Edward C. Kinzel, and Ming C. Leu. “Thermal Stress Prediction in Laser Powder Bed Fusion.” In 2023 International Solid Freeform Fabrication Symposium. 2023..
Liu, Tao, Edward C. Kinzel, and Ming C. Leu. “In-situ lock-in thermographic measurement of powder layer thermal diffusivity and thickness in laser powder bed fusion.” Additive Manufacturing 74 (2023): 103726.
Sehhat, M. Hossein, Austin T. Sutton, Zane Yates, and Ming C. Leu. “Experimental approach for development of a powder spreading metric in additive manufacturing.” The International Journal of Advanced Manufacturing Technology 126, no. 1-2 (2023): 371-380.
2022
Liu, Tao, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, and Ming C. Leu. “In-situ infrared thermographic inspection for local powder layer thickness measurement in laser powder bed fusion.” Additive Manufacturing 55 (2022): 102873.
Liu, Tao, Edward C. Kinzel, and Ming C. Leu. “In-situ Infrared Thermographic Measurement of Powder Properties in Laser Powder Bed Fusion.” In 2022 International Solid Freeform Fabrication Symposium. 2022.
Lough, Cody S., Tao Liu, Xin Wang, Ben Brown, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, and Edward C. Kinzel. “Local prediction of Laser Powder Bed Fusion porosity by short-wave infrared imaging thermal feature porosity probability maps.” Journal of Materials Processing Technology 302 (2022): 117473.
2021
Ren, Yi Ming, Yichi Zhang, Yangyao Ding, Tao Liu, Cody S. Lough, Ming C. Leu, Edward C. Kinzel, and Panagiotis D. Christofides. “Finite element modeling of direct metal laser solidification process: Sensor data replication and use in defect detection and data reduction via machine learning.” Chemical Engineering Research and Design 171 (2021): 254-267.
Liu, Tao, Cody S. Lough, Hossein Sehhat, Jie Huang, Edward C. Kinzel, and Ming C. Leu. “In-situ thermographic inspection for laser powder bed fusion.” In 2021 International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2021.
Sehhat, M. Hossein, Austin T. Sutton, Chia-Hung Hung, Joseph W. Newkirk, and Ming C. Leu. “Investigation of mechanical properties of parts fabricated with gas-and water-atomized 304L stainless steel powder in the laser powder bed fusion process.” JOM (2021): 1-8.
Rodriguez-Morales, Fernando, Ben Brown, Austin Sutton, Ming Leu, Frank Liou, Sean Garrison, and Ambrose Wolf. “Additively Manufactured Interdigital Filters for Ultra-Wideband Radar.” In 2021 IEEE Radio and Wireless Symposium (RWS), pp. 137-140. IEEE, 2021.
2020
Lough, Cody S., Xin Wang, Christopher C. Smith, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, Ben Brown, and Edward C. Kinzel. “Correlation of SWIR imaging with LPBF 304L stainless steel part properties.” Additive Manufacturing 35 (2020): 101359.
Sutton, Austin T., Caitlin S. Kriewall, Sreekar Karnati, Ming C. Leu, and Joseph W. Newkirk. “Characterization of AISI 304L stainless steel powder recycled in the laser powder-bed fusion process.” Additive Manufacturing 32 (2020): 100981.
Sutton, Austin T., Caitlin S. Kriewall, Ming C. Leu, Joseph W. Newkirk, and Ben Brown. “Characterization of laser spatter and condensate generated during the selective laser melting of 304L stainless steel powder.” Additive Manufacturing 31 (2020): 100904.
Sutton, Austin T., Caitlin S. Kriewall, Sreekar Karnati, Ming C. Leu, Joseph W. Newkirk, Wes Everhart, and Ben Brown. “Evolution of AISI 304L stainless steel part properties due to powder recycling in laser powder-bed fusion.” Additive Manufacturing 36 (2020): 101439.
2018
Tao, Wenjin, Austin Sutton, Krishna Kolan, Yong Liu, and Ming C. Leu. “Design of Lattice Structures with Graded Density Fabricated by Additive Manufacturing.” In Proceedings of the International Symposium on Flexible Automation 2018, pp. 122-125. The Institute of Systems, Control and Information Engineers, 2018.
Sutton, Austin T., Caitlin S. Kriewall, Ming C. Leu, and Joseph W. Newkirk. “Recyclability of 304L Stainless Steel in the Selective Laser Melting Process.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2018.
2017
Sutton, Austin T., Caitlin S. Kriewall, Ming C. Leu, and Joseph W. Newkirk. “Powder characterisation techniques and effects of powder characteristics on part properties in powder-bed fusion processes.” Virtual and physical prototyping 12, no. 1 (2017): 3-29.
Thomas, Baily, Austin T. Sutton, Ming C. Leu, and Nikhil Doiphode. “Bonding of 304L Stainless Steel to Cast Iron by Selective Laser Melting.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2017.
Thomas, Baily, Austin Sutton, and Ming C. Leu. “Study of Selective Laser Melting for Bonding of 304L Stainless Steel to Grey Cast Iron.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2017.
Kriewall, Cairlin S., Austin T. Sutton, Sreekar Karnati, Joseph William Newkirk, and Ming C. Leu. “Effects of area fraction and part spacing on degradation of 304L stainless steel powder in selective laser melting.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2017.
2016
Sutton, Austin T., Caitlin S. Kriewall, Ming C. Leu, and Joseph William Newkirk. “Powders for additive manufacturing processes: Characterization techniques and effects on part properties.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2016.
Kriewall, Caitlin S., Austin T. Sutton, Ming C. Leu, Joseph William Newkirk, and Ben Brown. “Investigation of heat-affected 304L SS powder and its effect on built parts in selective laser melting.” In International Solid Freeform Fabrication Symposium. University of Texas at Austin, 2016.