Thermographic investigation of laser-induced temperature fields in selective laser beam melting of polymers

Abstract

Selective laser beam melting of polymers is one of the most promising additive manufacturing technologies. Still, the main challenge is to enhance the reproducibility of part properties. To achieve this, better understanding and adapting the basic material beam interactions is crucial for the resulting temperature fields and local temperature development in xy- and z-direction. Therefore, thermographic infrared measurements were conducted within a selective beam melting system to determine the resulting temperature fields during laser exposure in xy-direction. The present results indicate a strong influence of process parameters, such as scan speed, laser power and scan vector length on resulting temperatures during and after exposure. A major influence of scan speed and therefore impact time on resulting maximum temperature was found. The shown results indicate the strongly time- and geometry- dependent influence of scan parameters on the melting and aging behavior of PA 12. For generating optimal properties of laser beam molten parts, the exposure parameters should be adapted according to the parts geometry.