Selective laser sintering of glass-ceramic powders by CO2 laser radiation

D. Correa-Coyac, A. Ramos-Velazquez, A. Michtchenko, R. Zenteno-Garcia
Instituto Politécnico Nacional,
Mexico

Keywords: glass-ceramic, 3D printing, sintering, CO2 laser

Summary:

The last years rapid prototyping technologies are widely used in the automotive, aeronautical and medical industry. The principle of Selective Laser Sintering (SLS) is to manufacture a three-dimensional object based on a computer 3D model divided into layers of a certain thickness. The control computer processing unit receives information about each layer and then a laser is used as an energy source to melt and specific area of a bed powder material. Currently, most popular powder materials used in manufacturing are metal or polymer materials. The low melting point of these materials facilitates the melting process. However, duo to the high melting point, strong strength at high temperature and low thermal conductivity the application of ceramic materials is limited in the technology of selective laser melting. The aim of this work is to develop the experimental setup to produce a layer-by-layer sintering of glass-ceramic powder with the assistance of a continuous wave (CW) carbon dioxide (CO2) laser with a wavelength of 10.64 µm. This setup will also allow to study the process of selective sintering products under the action of different scanning velocities of laser radiation and power density. In addition, microstructure, powder bed thickness, deformation, micro-hardness and relative density of 3D printings will be analysed. An experimental arrangement with a 100W CW CO2 laser is proposed, the power density is regulated by a control system, which also controls the interaction time of laser radiation with the sample and the formation of powder beds with thickness from 10-100 μm. The glass-ceramic powder material from the system SiO2-Na2O-ZnO-CaO-B2O3-Al2O3-CoO is characterized using energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM) and grain size analysis. The structure morphology and phase transformation during the fabrication are also analysed.