scholarly journals Surface modification as a technique to improve inter-layer bonding strength in 3D printed cementitious materials

2019 ◽  
Vol 4 ◽  
pp. 33-38 ◽  
Author(s):  
Jolien Van Der Putten ◽  
Geert De Schutter ◽  
Kim Van Tittelboom
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Bonding Strength ◽  
Substrate Surface ◽  
Cementitious Materials ◽  
Degree Of Hydration ◽  
Custom Made ◽  
Wire Brushing ◽  
Modification Technique ◽  
3D Printed

The structural capacity of 3D printed components mainly depends on the inter-layer bonding strength between the different layers. This bond strength is affected by many parameters (e.g. moisture content of the substrate, time gap, surface roughness,..) and any mismatch in properties of the cementitious material may lead to early failure. A common technique to improve inter-layer bonding strength between a substrate and a newly added layer is modifying the substrate surface. For the purpose of this research, a custom-made 3D printing apparatus is used to simulate the printing process and layered specimens with a different delay time (0 and 30 minutes) are manufactured with different surface modification techniques (wire brushing, addition of sand or cement and moisturizing substrate layer). The surface roughness was measured and the effect of the modification technique on the inter-layer-bonding strength was investigated. Results showed that the most effective way to increase the inter-layer bonding is increasing the surface roughness by a comb. This creates a kind of interlock system that will provide a higher inter-layer strength. The compressive strength is most influenced by the addition of cement, where the changing W/C-ratio will create a higher degree of hydration and consequently a higher strength.

scholarly journals Surface Functionalization of Three Dimensional-Printed Polycaprolactone-Bioactive Glass Scaffolds by Grafting GelMA Under UV Irradiation

2020 ◽  
Vol 7 ◽  
Author(s):  
Farnaz Ghorbani ◽  
Melika Sahranavard ◽  
Zohre Mousavi Nejad ◽  
Dejian Li ◽  
Ali Zamanian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Roughness ◽  
Surface Modification ◽  
Bioactive Glass ◽  
Uv Irradiation ◽  
Three Dimensional ◽  
Homogeneous Distribution ◽  
X Ray ◽  
Fused Deposition ◽  
3D Printed

In this study, bioactive glass nanoparticles (BGNPs) with an average diameter of less than 10 nm were synthesized using a sol-gel method and then characterized by transmission electron microscopy (TEM), differential scanning calorimetric (DSC), Fourier transforms infrared spectroscopy (FTIR), and x-ray spectroscopy (XRD). Afterward, three dimensional (3D)-printed polycaprolactone (PCL) scaffolds along with fused deposition modeling (FDM) were incorporated with BGNPs, and the surface of the composite constructs was then functionalized by coating with the gelatin methacryloyl (GelMA) under UV irradiation. Field emission scanning electron microscopy micrographs demonstrated the interconnected porous microstructure with an average pore diameter of 260 µm and homogeneous distribution of BGNPs. Therefore, no noticeable shrinkage was observed in 3D-printed scaffolds compared with the computer-designed file. Besides, the surface was uniformly covered by GelMA, and no effect of surface modification was observed on the microstructure while surface roughness increased. The addition of the BGNPs the to PCL scaffolds showed a slight change in pore size and porosity; however, it increased surface roughness. According to mechanical analysis, the compression strength of the scaffolds was increased by the BGNPs addition and surface modification. Also, a reduction was observed in the absorption capacity and biodegradation of scaffolds in phosphate-buffered saline media after the incorporation of BGNPs, while the presence of the GelMA layer increased the swelling potential and stability of the composite matrixes. Moreover, the capability of inducing bio-mineralization of hydroxyapatite-like layers, as a function of BGNPs content, was proven by FE-SEM micrographs, EDX spectra, and x-ray diffraction spectra (XRD) after soaking the obtained samples in concentrated simulated body fluid. A higher potential of the modified constructs to interact with the aqueous media led to better precipitation of minerals. According to in-vitro assays, the modified scaffolds can provide a suitable surface for the attachment and spreading of the bone marrow mesenchymal stem cells (BMSCs). Furthermore, the number of the proliferated cells confirms the biocompatibility of the scaffolds, especially after a modification process. Cell differentiation was verified by alkaline phosphatase activity as well as the expression of osteogenic genes such as osteocalcin and osteopontin. Accordingly, the scaffolds showed an initial potential for reconstruction of the injured bone.

Structural Changes in TiO2 Films Formed by Anodizing of Electro-Polished Titanium

2016 ◽  
Vol 869 ◽  
pp. 689-692
Author(s):  
Patricia López Díaz ◽  
Marinalda Claudete Pereira ◽  
Eduardo Norberto Codaro ◽  
Heloisa Andréa Acciari
Keyword(s):  
Surface Roughness ◽  
Raman Spectroscopy ◽  
Surface Modification ◽  
Direct Current ◽  
Structural Changes ◽  
Polarized Light ◽  
Applied Potential ◽  
Granular Microstructure ◽  
Crystalline Films ◽  
Modification Technique

Anodizing is a surface modification technique that is applied to growing oxide films on Ti to accelerate the osseointegration of an implant. Besides the surface roughness, the crystalline structure of these films can affect its performance as a biomaterial. For this reason, this technique has been refined to produce crystalline films without requiring heat treatments. For this purpose, TiO2 films were grown on Ti (grade 2) by anodizing with direct current at different potentials. Images obtained by optical microscopy with polarized light revealed a granular microstructure in various colors, as consequence of different crystalline orientations of the grains and films thickness. Raman spectroscopy showed that the films crystallinity is affected by variations in the applied potential and anodizing time.

Study on Characteristics of ADI Coated DLC/ TiN /TiAlN Coatings by Cathodic Arc Evaporation

2006 ◽  
Vol 118 ◽  
pp. 257-264 ◽  
Author(s):  
Cheng Hsun Hsu ◽  
Jung Kai Lu ◽  
Ming Li Chen
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Surface Modification ◽  
Substrate Surface ◽  
Surface Hardness ◽  
High Carbon ◽  
Cathodic Arc Evaporation ◽  
Nodular Graphite ◽  
Arc Evaporation ◽  
Cathodic Arc

In this study, austempered ductile iron (ADI) substrate containing acicular ferrite and high-carbon austenite in the microstructure is made by austempering treatment at 360. Cathodic arc evaporation (CAE) coating technique was used to coat DLC, TiN and TiAlN films on ADI for surface modification. The results showed that the three coatings could be successfully coated onto ADI through CAE process without altering the unique microstructure of ADI. The structures of the coatings were identified by XRD, Raman and TEM, respectively. After HRC indentation testing, it was found that nodular graphite was the initial site of cracking for the coatings and then peeled. Surface roughness of all coated specimens was increased because the droplets generated on the substrate surface during the CAE process. Coated ADI had better wearability performance than uncoated ADI due to higher surface hardness. Coated specimens exhibited higher corrosion resistance than uncoated ones when they were immersed in separate solutions of both 3.5 wt. % NaCl and 10 vol. % HCl. In particular, TiAlN had the best corrosion resistance among the coated specimens.

Powder Mixed Electric Discharge Machining: An Innovative Surface Modification Technique to Enhance Fatigue Performance and Bioactivity of β-Ti Implant for Orthopedics Application

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Chander Prakash ◽  
H. K. Kansal ◽  
B. S. Pabla ◽  
Sanjeev Puri
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Electric Discharge ◽  
Fatigue Behavior ◽  
Research Work ◽  
Fatigue Performance ◽  
Electric Discharge Machining ◽  
Local Factor ◽  
Modification Technique ◽  
Fatigue Endurance

The development of surface modification technique has been the subject of the studies regarding the fatigue performance and biological characterization of the modified layers. In the present research work, powder mixed electric discharge machining (PMEDM) a novel nonconventional machining technique has been proposed for surface modification of β-Ti implant for orthopedics application. The surface topography and morphology like roughness, surface cracks, and recast layer thickness of each of the machined specimens were investigated using Mitutoyo surface roughness tester and field-emission scanning electron microscopy (FE-SEM), respectively. This study aims to investigate the effect of surface characteristics of PMEDM process on the fatigue performance and bioactivity of β-Ti implants and moreover a comparative analysis is made on the fatigue performance and biological activity of specimens machined with presently used machining methods like electric discharge machining (EDM) and mechanical polishing. The high cycle fatigue (HCF) performance of polished specimens was superior and had no adverse effect of microstructure on fatigue endurance. As expected, the fatigue behavior of β-Ti implant-based alloy, after undergoing EDM treatment, is poorly observed due to the microrough surface. The fatigue performance is dependent on microstructure and surface roughness of the specimens. Subsequent PMEDM process significantly improves the fatigue endurance of β-Ti implant-based alloy specimens. PMEDMed surface with micro-, sub-micro-, and nano-structured topography exhibited excellent bioactivity and improved biocompatibility. PMEDMed surface enabled better adhesion and growth of MG-63 when compared with the polished and EDMed substrate. Furthermore, the differentiation results indicated that a combination of nanoscale featured submicrorough PMEDMed surface promotes various osteoblast differentiation activities like alkaline phosphatase (ALP) activity, osteocalcin production, the local factor osteoprotegerin, which inhibits osteoclastogenesis.

THE PHENOMENON OF SURFACE MODIFICATION BY ELECTRO-DISCHARGE COATING PROCESS: A REVIEW

2018 ◽  
Vol 25 (01) ◽  
pp. 1830003 ◽  
Author(s):  
SUJOY CHAKRABORTY ◽  
SIDDHARTHA KAR ◽  
VIDYUT DEY ◽  
SUBRATA KUMAR GHOSH
Keyword(s):  
Surface Modification ◽  
Substrate Surface ◽  
Tool Material ◽  
Machining Process ◽  
Machining Processes ◽  
Workpiece Material ◽  
Modification Technique ◽  
Inherent Nature ◽  
Conventional Machining ◽  
Edm Process

Electro-discharge machining (EDM) process is one of the most successful non-conventional machining processes for the last three to four decades in machining very hard materials which are tough to machine by conventional machining process. In the EDM process, besides the erosion of workpiece material, the inherent nature of the process leads to some tool material removal also. This nature of EDM process has been exploited by the researchers which led to the invention of Electro-discharge coating (EDC). EDC is a surface modification technique where tool material gets deposited on the substrate surface due to the sparking effect. It works on reverse polarity to that of EDM. A literature review based on the phenomenon of surface improvement by EDC process and also the future drifts of its application are shown in this paper.

scholarly journals Surface modification of fused filament fabrication (FFF) 3D printed substrates by inkjet printing polyimide for printed electronics

2020 ◽  
Vol 36 ◽  
pp. 101544
Author(s):  
Devin J. Roach ◽  
Christopher Roberts ◽  
Janet Wong ◽  
Xiao Kuang ◽  
Joshua Kovitz ◽  
...  
Keyword(s):  
Surface Modification ◽  
Inkjet Printing ◽  
Printed Electronics ◽  
Fused Filament Fabrication ◽  
3D Printed

scholarly journals Mechanical Characterization and Thermodynamic Analysis of Laser-Polished Landscape Design Products Using 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2601
Author(s):  
Yue Ba ◽  
Yu Wen ◽  
Shibin Wu
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
High Surface ◽  
Landscape Design ◽  
Laser Polishing ◽  
Fused Deposition ◽  
Design Structure ◽  
3D Printed ◽  
Stability And Accuracy

Recent innovations in 3D printing technologies and processes have influenced how landscape products are designed, built, and developed. In landscape architecture, reduced-size models are 3D-printed to replicate full-size structures. However, high surface roughness usually occurs on the surfaces of such 3D-printed components, which requires additional post-treatment. In this work, we develop a new type of landscape design structure based on the fused deposition modeling (FDM) technique and present a laser polishing method for FDM-fabricated polylactic acid (PLA) mechanical components, whereby the surface roughness of the laser-polished surfaces is reduced from over Ra 15 µm to less than 0.25 µm. The detailed results of thermodynamics and microstructure evolution are further analyzed during laser polishing. The stability and accuracy of the results are evaluated based on the standard deviation. Additionally, the superior tensile and flexural properties are examined in the laser-polished layer, in which the ultimate tensile strength (UTS) is increased by up to 46.6% and the flexural strength is increased by up to 74.5% compared with the as-fabricated components. Finally, a real polished landscape model is simulated and optimized using a series of scales.

scholarly journals 3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

2021 ◽  
Vol 11 (6) ◽  
pp. 2563
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Biomechanical Properties ◽  
Testing Procedure ◽  
Laboratory Equipment ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

scholarly journals Recurrent contracted sockets treated with personalized, three-dimensionally printed conformers and buccal grafts

2021 ◽  
pp. 112067212110000
Author(s):  
Annabel LW Groot ◽  
Jelmer S Remmers ◽  
Roel JHM Kloos ◽  
Peerooz Saeed ◽  
Dyonne T Hartong
Keyword(s):  
Three Dimensional ◽  
Case Series ◽  
Secondary Outcome ◽  
Retrospective Case ◽  
Upper Eyelid ◽  
Ocular Prosthesis ◽  
Buccal Mucosal Graft ◽  
Custom Made ◽  
3D Printed

Purpose: Recurrent contracted sockets are complex situations where previous surgeries have failed, disabling the wear of an ocular prosthesis. A combined method of surgery and long-term fixation using custom-made, three-dimensional (3D) printed conformers is evaluated. Methods: Retrospective case series of nine patients with recurrent excessive socket contraction and inability to wear a prosthesis, caused by chemical burns ( n = 3), fireworks ( n = 3), trauma ( n = 2) and enucleation and radiotherapy at childhood due to optic nerve glioma ( n = 1) with three average previous socket surgeries (range 2–6). Treatment consisted of a buccal mucosal graft and personalized 3D-printed conformer designed to be fixated to the periosteum and tarsal plates for minimal 2 months. Primary outcome was the retention of an ocular prosthesis. Secondary outcome was the need for additional surgeries. Results: Outcomes were measured at final follow-up between 7 and 36 months postoperatively (mean 20 months). Eight cases were able to wear an ocular prosthesis after 2 months. Three cases initially treated for only the upper or only the lower fornix needed subsequent surgery for the opposite fornix for functional reasons. Two cases had later surgery for cosmetic improvement of upper eyelid position. Despite pre-existing lid abnormalities (scar, entropion, lash deficiency), cosmetic outcome was judged highly acceptable in six cases because of symmetric contour and volume, and reasonably acceptable in the remaining two. Conclusions: Buccal mucosal transplant fixated with a personalized 3D-designed conformer enables retention of a well-fitted ocular prosthesis in previously failed socket surgeries. Initial treatment of both upper and lower fornices is recommended to avoid subsequent surgeries for functional reasons.

scholarly journals 3D-Printed Connector for Revision Limb Salvage Surgery in Long Bones Previously Using Customized Implants

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 707
Author(s):  
Jong-Woong Park ◽  
Hyun-Guy Kang ◽  
June-Hyuk Kim ◽  
Han-Soo Kim
Keyword(s):  
Limb Salvage ◽  
Salvage Surgery ◽  
Revisional Surgery ◽  
Limb Salvage Surgery ◽  
Musculoskeletal Tumor ◽  
Musculoskeletal Tumor Society ◽  
Proximal Ulna ◽  
Custom Made ◽  
Orthopedic Oncology ◽  
3D Printed

In orthopedic oncology, revisional surgery due to mechanical failure or local recurrence is not uncommon following limb salvage surgery using an endoprosthesis. However, due to the lack of clinical experience in limb salvage surgery using 3D-printed custom-made implants, there have been no reports of revision limb salvage surgery using a 3D-printed implant. Herein, we present two cases of representative revision limb salvage surgeries that utilized another 3D-printed custom-made implant while retaining the previous 3D-printed custom-made implant. A 3D-printed connector implant was used to connect the previous 3D-printed implant to the proximal ulna of a 40-year-old man and to the femur of a 69-year-old woman. The connector bodies for the two junctions of the previous implant and the remaining host bone were designed for the most functional position or angle by twisting or tilting. Using the previous 3D-printed implant as a taper, the 3D-printed connector was used to encase the outside of the previous implant. The gap between the previous implant and the new one was subsequently filled with bone cement. For both the upper and lower extremities, the 3D-printed connector showed stable reconstruction and excellent functional outcomes (Musculoskeletal Tumor Society scores of 87% and 100%, respectively) in the short-term follow-up. To retain the previous 3D-printed implant during revision limb salvage surgery, an additional 3D-printed implant may be a feasible surgical option.

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