Recent research has shown that thermal spray has the potential to fabricate thermoelectric devices at low cost and high volumes. An integral aspect of the device fabrication is laser processing of the various thermal sprayed layers, which is used to form electrically isolated regions and minimize heat loss to adjacent structures. In this article, experimental results are presented for the laser patterning of thermal spray samples ranging from 50μm to 2mm in thickness. The optimization of process parameters is important for successful electrical isolation and high-quality features. In this study results are presented several short-pulse lasers (nanosecond and picosecond) in which laser power, laser wavelength, type of focusing lens, processing speed, repetition rate, and pressure and flow of purge gas were varied. The optimum laser parameters were those that minimize the heat affected zone and delamination due to thermal damage while providing maximum material removal. The resulting laser patterns were characterized using both optical and scanning electron (SEM) microscopy, and by verifying electrical isolation between patterned regions using contact resistance measurements. Cut quality attributes including kerf width and edge profile were also studied, and their dependence on process parameters reported.
- Heat Transfer Division
Laser Processing of Thermal Sprayed Coatings for Thermoelectric Generators Available to Purchase
Tewolde, M, Liu, D, Hwang, DJ, & Longtin, JP. "Laser Processing of Thermal Sprayed Coatings for Thermoelectric Generators." Proceedings of the ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology. Volume 3: Gas Turbine Heat Transfer; Transport Phenomena in Materials Processing and Manufacturing; Heat Transfer in Electronic Equipment; Symposium in Honor of Professor Richard Goldstein; Symposium in Honor of Prof. Spalding; Symposium in Honor of Prof. Arthur E. Bergles. Minneapolis, Minnesota, USA. July 14–19, 2013. V003T09A010. ASME. https://doi.org/10.1115/HT2013-17791
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