Abstract—Additive manufacturing of high-performance materials such as polyether ether ketone (PEEK) is constantly gaining attention because of its applications in diverse fields. PEEK is a semicrystalline thermoplastic that exhibits superior mechanical properties, biocompatibility, and wear resistance that makes it suitable for biomedical and other industrial applications. Most of these applications call for surface designs where roughness and porosity are a major consideration.  In this study, PEEK samples with different surface designs were prepared by modifying slicing parameters such as wall line, infill density, and raster angle.  The samples were printed using fused deposition modelling and were characterized using a non-destructive method, X-ray micro computed tomography (X-ray micro-CT).  X-ray tomograms and void content analysis show that voids usually occur at the junction between the walls and the infill for all three designs. Reducing the infill travel path by adding inner walls resulted to higher defect volume ratio.  Defect volume ratio increased from 0.06% to 0.36% after the addition of inner walls. Reduction in infill density further increased the defect volume ratio.  These results show that different surface and internal designs can be prepared by modifying slicing parameters and its defects/void content can be readily evaluated by X-ray micro-CT.  
 
Index Terms—PEEK, FDM, 3D printing, slicing, X-ray computed tomography