Preparation of Alumina Particles Coated with a Thin Layer of Amorphous Thermoplastic via Phase Inversion Process for Indirect SLS Applications
Authors: Sayed mahmoud Nazemosadat arsanjani, Mohsen Badrossamay, Ehsan Foroozmehr
Abstract: Additive manufacturing or 3D printing processes through which applicable complicated parts are directly made based on 3D model of the part has been extensively addressed in numerous research and development tasks for the past years. Certain merits such as decline of time, cost of design and manufacturing of product, processing different engineering materials, manufacturing parts with highly complicated geometries, and manufacturing customized parts should be noted in the case of adopting these methods. Indirect selective laser sintering is one of the interesting methods of integrated manufacturing which could be used for manufacturing of complicated pieces and certain materials such as ceramics with a high melting point and difficult manufacturing process through typical methods. In the present study, indirect SLS of spherical alumina powder particles with a thin layer of amorphous thermoplastic (PMMA and PS). In order to coat alumina particles with different weight percent of thermoplastic, the new method of phase Inversion process was used. Due to significance of geometry and dimensions of the final part, the least probable thickness of thermoplastic was used for manufacturing of parts based on SLS method. In the present study, evaluation of coating and method of coating have been discussed. The evaluative techniques include assessment through scanning electron microscopy, analytical results of Fourier transform infrared spectroscopy and thermogravimetric analysis and differential scanning calorimetry. Finally, green parts where produced based SLS method and through optimal values of laser parameters and selection of alumina powder particles with thinnest thermoplastic coating.