Temperature Monitoring and Overhang Layers Problem

The principles of measuring the surface temperature of powder bed in the focal spot of the laser radiation while scanning the surface using galvoscanner with F-teta lens have been designed. The optical system provide the possibility to measure spatial distribution of brightness temperature at two wavelengths and selected temperature profiles, calculation of colour temperature and maximum temperature in focal spot. Investigation of the sintering of overhang layers has been conducted under temperature monitoring and Rayleigh - Taylor instability of the contact surface between melt and loose powder in a gravity field was found.