Thermographie zur Temperaturmessung beim Laser-Sintern �? ein Beitrag zur Qualitätssicherung?

RTejournal - Forum für Rapid Technologie

Andreas Wegner¹  Gerd Witt¹ 

[1]Universität Duisburg-Essen

关键词: Generative Fertigungsverfahren;    Laser Sintering;    Qualitätssicherung;    Prozessüberwachung;    Thermographie;    Temperaturmessung;   

DOI  :  

学科分类：社会科学、人文和艺术（综合）

来源: DiPP NRW

【 摘 要 】

The powder bed surface in laser sintering is preheated to a temperature close to the material’s melting point by a radiant heater. The distribution of temperatures on the surface should be as homogeneous as possible to achieve equal part properties in the whole build space and to get minor part warpage. However, experiences show very inhomogeneous temperature distributions. Therefore, it is often asked for the integration of new process monitoring systems in the machines. One possible solution to perform this task is thermal imaging, which enables a 2-dimensional measurement of surface temperatures and can give information on the temperature of the powder bed surface. Thereby, cold areas can be detected on the surface and can be considered in pre-processing. Additionally thermal imaging enables the monitoring of the temperature while the laser is working and therefore it gives the possibility to establish correlations between the process parameters and the temperature of the melt. Within the scope of the analysis done, a thermal imaging system was successfully integrated in a laser sintering machine. At the same time, necessary solutions were developed for the problems which emerged from the integration of the system. Afterwards, the temperature distribution on the part bed surface was determined. Additionally, influence factors on the homogeneity of the part bed surface’s temperature were analysed. Further analysis was done to determine the temperature of the melt as a function of different process parameters. Conclusions for required optimisations were educed from the measurement results; and the usability of thermal imaging in laser sintering for process monitoring, process control and maintenance was evaluated as a first intermediate result of the analysis.

【 授权许可】

Unknown