The fused filament fabrication (FFF) of ceramics enables the additive manufacturing of components with complex geometries for many applications like tooling or prototyping. Nevertheless, due to the many factors involved in the process, it is difficult to separate the effect of the different parameters on the final properties of the FFF parts, which hinders the expansion of the technology. In this paper, the effect of the fill pattern used during FFF on the defects and the mechanical properties of zirconia components is evaluated. The zirconia-filled filaments were produced from scratch, characterized by different methods and used in the FFF of bending bars with infill orientations of 0°, ±45° and 90° with respect to the longest dimension of the specimens. Three-point bending tests were conducted on the specimens with the side in contact with the build platform under tensile loads. Next, the defects were identified with cuts in different sections. During the shaping by FFF, pores appeared inside the extruded roads due to binder degradation and or moisture evaporation. The changes in the fill pattern resulted in different types of porosity and defects in the first layer, with the latter leading to earlier fracture of the components. Due to these variations, the specimens with the 0° infill orientation had the lowest porosity and the highest bending strength, followed by the specimens with ±45° infill orientation and finally by those with 90° infill orientation.

The obtaining of dense ceramic pieces with versatility of size and shape is a much sought-after objective. Powder Injection Moulding (PIM) and Ceramic Injection Moulding (CIM), in particular, is a well-known technology that allows preparing this kind of complex parts with great variety of materials and at large production volume in a cost-efficient way. Usually, this process provides structural materials for mechanical and conforming purposes, but very few works have focused on manufacture functional porcelains. In this work, CIM method is used to process rare-earth free glass-ceramics with photoluminescent properties. The CIM parameters are optimized to obtain dense ceramic parts based on Na-rich plagioclase previously designed. The CIM processed samples show a higher structural disorder as studied by XRD and Raman spectroscopy and variations of the micro-nanostructure, in comparison with conventional ceramic processed samples. Photoluminescent emission studies show an increase of almost one order of magnitude on the UV-blue emission, due to the rise of the structural defect population generated by the CIM process. The CIM process, thus, provides results that boosted the use of rare-earth free materials for luminescence application having complex shapes.

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