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 this work, an innovative phase inversion technique is used to fabricate spherical alumina particles coated with a thin layer of polystyrene (PS). Then, indirect SLS is used to fabricate green parts from the 2-15wt % PS (PMMA) coated alumina particles via a Nd:YAG laser. The assessed SLS process parameters were the scan speed, laser power, scan spacing, pulse frequency, and pulse width. The characterization of the AL 2 O 3 /PS(PMMA) core-shell composite particles was described using techniques including SEM (for morphology), FT-IR (for chemical bonding at the interfaces), TGA (for mass loss), and DSC (for glass transition temperature, T g ). 3D green parts were then fabricated using proper process parameters as a proof of the feasibility of using SLS technique for AL 2 O 3 /PS core-shell composite powder. The results showed that using a Nd:YAG laser with less absorption by alumina and PS provides greater penetration through a powder bed. In addition, the possibility of sound connections among particles in every direction was observed due to the uniformity of the coating process in spite of a minimal amount of binder. In addition, green part density measurements show high values compared to previously reported results. In numerical simulations, considering laser as electromagnetic wave, electromagnetic modeling and the heat generated by the interaction of the electromagnetic field with powder particles was investigated in the COMSOL Multiphysics software version 5.2. In order to study the possibility of increasing the laser penetration in the powder substrate, adding the percentage of silica powder to the alumina powder was investigated. Also, the effects of the volume ratio of alumina particles to silica on the laser penetration depth was studied. The results of numerical simulation with the layer thickness will be compared experimentally. Keywords: Indirect selective laser sintering; spherical alumina powder; core-shell composite powder, phase inversion proce thermoplastic
