Analytical modelling of in-situ layer-wise defect detection in 3D Printed parts: Additive Manufacturing

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This study analyses a software algorithm developed on MATLAB, which can be used to examine fused filament fabrication-based 3D printed materials for porosity and other defects that might affect the mechanical property of the final component under manufacture or the general aesthetic quality of a product. An in-depth literature review into the 3D printed materials reveals a rapidly increasing trend in its application in the industrial sector. Hence the quality of manufactured products cannot be compromised. Despite much research found to be done on this subject, there is still little or no work reported on porosity or defect detection in 3D printed components during (real-time) or after manufacturing operation. The algorithm developed in this study is tested for two different 3-D object geometry and the same filament color. The results showed that the algorithm effectively detected the presence or absence of defects in a 3D printed part geometry and filament colors. Hence, this technique can be generalized to a considerable range of 3-D printer geometries, which solve material wastages by spotting defects during the workpieces layer-wise manufacturing process, thereby improving the economic advantages of additive manufacturing

Enhancing dimensional accuracy in 3D printing: a novel software algorithm for real-time quality assessment

Notably, despite the widespread application of 3D printing technology across diverse industries, issues like dimensional variations continue to limit its full-scale production potential. In this research, the dimensional variation between the CAD model and a 3D printed specimen by extrusion technique is investigated by a developed software algorithm. In contrast to previously employed techniques such as coordinate measuring machines, laser scanning, optical profilometry, and CT scanning, which have been highlighted in the literature, the developed software algorithm is cheap and stands out by relying on computer vision for the assessment of dimensional deviations in the printed model. The proposed software algorithm assesses the dimensional quality of 3D printed components through a comprehensive three-step methodology: preparation, measurement, and analysis. The software scrutinizes both the CAD model and the G-code-sliced model, extracting crucial dimensional data that serves as a reference for monitoring deviations during the actual 3D printing process. The software is fully tested across a diverse 3D geometry, capable of predicting real-time dimensional variances that could otherwise result in printing failures. The solution not only ensures the preservation of economic and human resources in additive manufacturing but also enhances the overall efficiency of the process. The paper concludes that the choice of the appropriate method should be contingent on the specific part type and the level of accuracy required.</p

3D printing of PEEK–cHAp scaffold for medical bone implant

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The major drawback associated with PEEK implants is their biologically inert surface, which caused unsatisfactory cellular response and poor adhesion between the implants and surrounding soft tissues against proper bone growth. In this study, polyetheretherketone (PEEK) was incorporated with calcium hydroxyapatite (cHAp) to fabricate a PEEK–cHAp biocomposite, using the fused deposition modeling (FDM) method and a surface treatment strategy to create microporous architectures onto the filaments of PEEK lattice scaffold. Also, nanostructure and morphological tests of the PEEK–cHAp biocomposite were modeled and analyzed on the FDM-printed PEEK–cHAp biocomposite sample to evaluate its mechanical and thermal strengths as well as in vitro cytotoxicity via a scanning electron microscope (SEM). A technique was used innovatively to create and investigate the porous nanostructure of the PEEK with controlled pore size and distribution to promote cell penetration and biological integration of the PEEK–cHAp into the tissue. In vivo tests demonstrated that the surface-treated micropores facilitated the adhesion of newly regenerated soft tissues to form tight implant–tissue interfacial bonding between the cHAp and PEEK. The results of the cell culture depicted that PEEK–cHAp exhibited better cell proliferation attachment spreading and higher alkaline phosphatase activity than PEEK alone. Apatite islands formed on the PEEK–cHAp composite after immersion in simulated body fluid of Dulbecco's modified Eagle medium (DMEM) for 14 days and grew continuously with more or extended periods. The microstructure treatment of the crystallinity of PEEK was comparatively and significantly different from the PEEK–cHAp sample, indicating a better treatment of PEEK–cHAp. The in vitro results obtained from the PEEK–cHAp biocomposite material showed its biodegradability and performance suitability for bone implants. This study has potential applications in the field of biomedical engineering to strengthen the conceptual knowledge of FDM and medical implants fabricated from PEEK–cHAp biocomposite materials

Lattice design and 3D-printing of PEEK with Ca10(OH)(PO4)3 and in-vitro bio-composite for bone implant

© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/.The addition of biomaterials such as Calcium hydroxyapatite (cHAp) and incorporation of porosity into poly-ether-ether-ketone (PEEK) are effective ways to improve bone-implant interfaces and osseointegration of PEEK composite. Hence, the morphological effects of nanocomposite on surfaces biocompatibility of a newly fabricated composite of PEEK polymer and cHAp for a bone implant, using additive manufacturing (AM) were investigated. Fused deposition modeling (FDM) method and a surface treatment strategy were employed to create a microporous scaffold. PEEK osteointegration was slow and, therefore, it was accelerated by surface coatings with the incorporation of bioactive cHAp, with enhanced mechanical and biological behaviors for bone implants. Characterization of the new PEEK/cHAp composite was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC), mechanical tests of traction and flexion, thermal dynamic mechanical analysis (DMA). Also, the PEEK/cHAp induced the formation of apatite after immersion in the simulated body fluid of DMEM for different days to check its biological bioactivity for an implant. In-vivo results depicted that the osseointegration and the biological activity around the PEEK/cHAp composite were higher than that of PEEK. The increase in the mechanical performance of cHAp-coated PEEK can be attributed to the increase in the degree of crystallinity and accumulation of residual polymer.Peer reviewe