Operando high speed near infrared imaging during laser sintering of nanoparticles for time and space resolved temperature measurements

Abstract

Abstract A high-speed camera equipped with a near-infrared (NIR) microscope optic is employed for spatially resolved NIR thermal imaging during laser sintering. The device enables operando temperature measurements with a temporal resolution less than 1 ms and a spatial resolution better than 10 μm. The feasibility for in situ temperature measurements is demonstrated for resonant laser sintering of TiO 2 nanoparticles. The temperature range is calibrated at a framerate of 1,069 frames per second (fps) using a TiO 2 reference sample. The laser sintering process is observed at framerates of up to 15,969 fps. The resulting microstructure of the TiO 2 sample is analyzed by scanning electron microscopy (SEM) and interpreted in view of the recorded sintering temperature profiles.