32 Mound Laser Micromachining Process for Fabiricating SiC Mirrors
Laser Assisted High Pressure Phase Transformation in SiC
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Transcript of Laser Assisted High Pressure Phase Transformation in SiC
Principle Investigator: Dr. John PattenResearch Assistants: Saurabh R. Virkar and Thomas
Kremenski
Dr. Vitali Prakapenka examines a DAC
sample.
Argonne National Laboratory –Advance Photon Source
Synchrotron Facility in Chicago
At the heart of the experimentation was the diamond anvil cell (DAC). In order to simulate the stresses of machining, our specimen had to be subjected to pressures up to 100 GPa with temperature exceeding 2000˚ K by laser
Diamond Anvil Cell
The Diamond Anvil CellLaser Beam for heating the sample
Laser Beam for heating the sample
•To duplicate the pressure and temperature encountered during SiC machining
•To study the phase transformation at high pressure and temperature
•To better understand micro-laser machining process (µ-LAM)
Powder for 4H SiC in 150 µm tip diamond Powder of 4H SiC in 300 µm tip diamond Powder of 6H SiC in 150 µm tip diamond IPG Laser 100 W
Phase transition in 4H SiC at 66 GPa and 1550 K temperature Phase transition in 6H SiC at 88GPa and 1550 K temperature
Before Phase transition in 4H SiC After Phase transition in 4H SiC
X-ray diffraction pattern before (black line) and after phase transformation (pink line) in 4H SiC
Before phase transformation in 6H SiC
After phase transformation in 6H SiC
X-ray diffraction pattern before (black line) and after phase transformation (pink line) in 6H SiC
Data Analysis TEM of the sample µ- Raman to analyze the absorption at high pressure Assembly of Diamond Anvil Cell for next test