Shaping ceramics through indirect selective laser sintering

Abstract

Purpose The purpose of this paper is to compare different powder metallurgy (PM) processes to produce ceramic parts through additive manufacturing (AM). This creates the potential to rapidly shape ceramic parts with an almost unlimited shape freedom. In this paper, alumina (Al2O3) parts are produced, as Al2O3 is currently the most commonly used ceramic material for technical applications. Design/methodology/approach Variants of the following PM route, with indirect selective laser sintering (indirect SLS) as the AM shaping step, are explored to produce ceramic parts: powder synthesis, indirect SLS, binder removal and furnace sintering and alternative densification steps. Findings Freeform-shaped Al2O3 parts with densities up to approximately 90 per cent are obtained. Research limitations/implications The resulting Al2O3 parts contain inter-agglomerate pores. To produce higher-quality ceramic parts through indirect SLS, these pores should be avoided or eliminated. Originality/value The research is innovative in many ways. First, composite powders are produced using different powder production methods, such as temperature-induced phase separation and dispersion polymerization. Second, four different binder materials are investigated: polyamide (nylon-12), polystyrene, polypropylene and a carnauba wax – low-density polyethylene combination. Further, to produce ceramic parts with increased density, the following densification techniques are investigated as additional steps of the PM process: laser remelting, isostatic pressing and infiltration.

High‐temperature flexural strength of SiC ceramics prepared by additive manufacturing

“…Lv et al 15 fabricated SiC/SiC ceramics based on 3D printing and chemical vapor infiltration (CVI) technology. 9,[21][22][23] However, SiC ceramics prepared using additive manufacturing exhibit a low strength and relative density. Wang et al 17 used stereolithography-integrated liquid silicon infiltration method to fabricate C/ SiC composites.…”

“…20 In the past years, many other ceramics have been prepared by this technology. 9,[21][22][23] However, SiC ceramics prepared using additive manufacturing exhibit a low strength and relative density. Several processes have been reported to deal with the requirements, including polymer impregnation process (PIP) [24][25][26] and liquid silicon infiltration (LSI).…”

Postprocessing Study for the Controllable Structures of Ceramic Green Parts Realized by a Flexible Binder Jetting Printing (BJP) Solution

“…e indirect way first forms ceramic green parts via powder-bonding methods at room temperature or with low-power energy, followed by postprocessing, to guarantee the final ceramic products with strengthened performances [7][8][9][10][11]. Generally, only specific ceramic-based material systems are suitable for direct-way production due to the high melting point of ceramic components, so the indirect way is still the mainstream for ceramic AM [12].…”

Short fiber reinforced 3d printed ceramic composite with shear induced alignment

“…SLS method involves the use of high power laser beam to bond ceramic particles to each other locally [6, 7]. Localized temperature gradient during sintering process can generate high internal stresses which might cause lots of defects and micro cracks.…”