Competitive Advantages
- This unprecedented new capability to capture the full 3D thermographic information in the powder bed and melt pool can more thoroughly elucidate the thermal history during the M-AM processes, thereby better informing optimization of process parameters to mitigate thermal gradients, residual stresses, and porosity, thus yielding higher quality and faster build
- This technology complements and is compatible with established infrared (IR) thermometry techniques
- This technology will equip the US advanced manufacturing sector with novel metrology and quality control capabilities
Summary
The quality of metals produced in additive manufacturing is highly dependent on control of the temperature and heat flux. Yet the state of the art in metals additive manufacturing thermometry via passive infrared measurement requires a priori and real-time knowledge of the precise emissivity of the metal powder bed and melt pool surface, which is difficult to attain. To overcome this barrier, USF researchers are developing a novel hybrid thermometry technology combining acoustic and Raman thermometry. Raman thermometry works on the principle of measuring the Stokes shift of the Raman-active phonon modes of the material(s) of interest, and also by measuring the relative population densities between the Stokes and anti-Stokes Raman modes. Simultaneously, a dual-mode acoustical method is employed, including traditional ultrasound, typically used for Non-destructive testing and phased array acoustic transduction, typically used for medical ultrasonic imaging. Both the speed of the acoustic wave (a function of temperature) and thickness of the part produced are unknown, necessitating using dual-mode acoustical technique enabling accurate in-situ 3D plot of temperature as well as heat flux at the surface and any point within the part produced.
Experimental setup for hybrid Raman and acoustic thermometry
Desired Partnerships
- License
- Sponsored Research
- Co-Development