Development of Freeform Fabrication of Metals by Three Diminsional Micro-Welding

2007 ◽  
Vol 127 ◽  
pp. 189-194 ◽  
Author(s):  
T. Horii ◽  
M. Ishikawa ◽  
Soshu Kirihara ◽  
Yoshinari Miyamoto ◽  
Nobu Yamanaka
Keyword(s):  
Electrode Materials ◽  
Welding Parameters ◽  
Layer By Layer ◽  
Combined System ◽  
Manufacturing Method ◽  
Freeform Fabrication ◽  
Inconel 600 ◽  
3D Objects ◽  
Cad Cam ◽  
Thin Metal Wire

A newly developed freeform fabrication process named 3D Micro-Welding, which is a combined system of a micro-TIG welding and a layered manufacturing method, is demonstrated. Various refractory alloys such as Inconel, stainless steel, and Invar can be freeformed besides elemental metals like titanium. Small metal beads of ~1mm in diameter are formed by emitting micro arc to the top of a thin metal wire of 0.2mm diameter. A fused bead is welded to a metal substrate or previously formed beads. By continuing this process and building up beads layer by layer under the control of CAD/CAM system, 3D objects were produced. In this study, optimization of micro-welding parameters such as the waveform of pulsed arc current and electrode materials were investigated and simple 3D objects of Inconel 600, SUS 304, Invar 42 were formed. The interfaces between adjacent beads were joined well and no crack or pore existed in the formed objects. The density and Vickers hardness of Inconel 600 objects showed comparable values to the commercial Inconel alloy, however the yield strength and Young’s modulus was about 80% and 70% of that alloy, respectively.

On the Development of a Modular 3D Bioprinter for Research in Biomedical Device Fabrication

2015 ◽  
Author(s):  
Prashanth Ravi ◽  
Panos S. Shiakolas ◽  
Jacob C. Oberg ◽  
Shahid Faizee ◽  
Ankit K. Batra
Keyword(s):  
Modular Design ◽  
Solid Freeform Fabrication ◽  
Device Fabrication ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
University Of Texas ◽  
Freeform Fabrication ◽  
Biomedical Device ◽  
Individual Module ◽  
Cad Cam

Biomanufacturing research involving solid freeform fabrication techniques has become fairly widespread in recent times. The layer-by-layer building concept provides an opportunity towards the development of a modular 3D printer to broaden the scope of biomanufacturing research. This research discusses the features of a Custom Multi-Modality 3D Bioprinter (CMMB) developed in the MARS lab at the University of Texas at Arlington (http://mars.uta.edu/). The CMMB currently includes a number of printing modules; two Fused Filament Fabrication (FFF), one Photo Polymerization (PP), one Viscous Extrusion (VE) and one Inkjet (IJ). The development of the custom bioprinter and each module are discussed; focusing on the advantages of a modular design, and on the unique features present in each individual module. Select constructs fabricated using individual or a combination of modules are presented and discussed. Design of Experiments (DOE) principles employing statistical software were used to characterize the CMMB; interactions between fabrication process parameters and their effect on deposited strand characteristics were analyzed. These results were employed to improve the quality of subsequently fabricated constructs. Initial experiments and fabricated constructs demonstrate that the custom bioprinter is a novel CAD-CAM biomanufacturing platform for research in methodologies, materials and processes for the fabrication of biomedical devices.

A review of additive manufacturing applications in ophthalmology

2021 ◽  
pp. 095441192110280
Author(s):  
Arivazhagan Pugalendhi ◽  
Rajesh Ranganathan
Keyword(s):  
Additive Manufacturing ◽  
Treatment Planning ◽  
Physical Object ◽  
Layer By Layer ◽  
Case Examples ◽  
Manufacturing Method ◽  
3D Cad ◽  
Stl File ◽  
Potential Applications ◽  
Manufacturing Applications

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

Solid Freeform Fabrication of Al-Li 2199 via Controlled-Short-Circuit-MIG Welding

2011 ◽  
Vol 409 ◽  
pp. 843-848
Author(s):  
David W. Heard ◽  
Julien Boselli ◽  
Raynald Gauvin ◽  
Mathieu Brochu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Freeform Fabrication ◽  
Short Circuit ◽  
Lithium Concentration ◽  
Gas Metal Arc Welding ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Freeform Fabrication ◽  
Metal Arc Welding ◽  
Welding Processes

Aluminum-lithium (Al-Li) alloys are of interest to the aerospace and aeronautical industries as rising fuel costs and increasing environmental restrictions are promoting reductions in vehicle weight. However, Al-Li alloys suffer from several issues during fusion welding processes including solute segregation and depletion. Solid freeform fabrication (SFF) of materials is a repair or rapid prototyping process, in which the deposited feedstock is built-up via a layering process to the required geometry. Recent developments have led to the investigation of SFF processes via Gas Metal Arc Welding (GMAW) capable of producing functional metallic components. A SFF process via GMAW would be instrumental in reducing costs associated with the production and repair of Al-Li components. Furthermore the newly developed Controlled-Short-Circuit-MIG (CSC-MIG) process provides the ability to control the weld parameters with a high degree of accuracy, thus enabling the optimization of the solidification parameters required to avoid solute depletion and segregation within an Al-Li alloy. The objective of this study is to develop the welding parameters required to avoid lithium depletion and segregation. In the present study weldments were produced via CSC-MIG process, using Al-Li 2199 sheet samples as the filler material. The residual lithium concentration within the weldments was then determined via Atomic Absorption (AA) and X-ray Photoelectron Spectroscopy (XPS). The microstructure was analyzed using High Resolution Scanning Electron Microscopy (HR-SEM). Finally the mechanical properties of welded samples were determined through the application of hardness and tensile testing.

Continuous Liquid Interface Production of 3D Objects: An Unconventional Technology and its Challenges and Opportunities

2017 ◽  
Author(s):  
Judah Balli ◽  
Subha Kumpaty ◽  
Vince Anewenter
Keyword(s):  
3D Printing ◽  
Industrial Applications ◽  
Research Literature ◽  
Liquid Interface ◽  
Layer By Layer ◽  
Support Structure ◽  
Practical Applications ◽  
3D Objects ◽  
Continuous Liquid Interface Production ◽  
Part Orientation

The purpose of this paper is to understand and research literature on the “continuous liquid interface production (CLIP)” of 3D objects to address the current challenges. This proprietary technology was originally owned by EiPi Systems but is now being developed by Carbon 3D. Unlike conventional rapid prototyping of printing layer-by-layer to print 3D objects, CLIP is achieved with an oxygen-permeable window made of proprietary glass membrane and the ultraviolet image projection plane below it, which allows the continuous liquid interface to produce 3D objects where photo-polymerization is restricted between the window and the polymerizing part. This process eliminates the time requirement in between the layers resulting in the faster production of 3D objects with a resolution less than 100 microns. It is a known factor that the “supports” play a vital role in any liquid based 3D printing techniques and this does not change in CLIP. In addition to the parameters of support structure like shape, size, strength, ease of removability, surface finish after removal of supports etc, CLIP needs to deal with different types of materials. The support structure needs to be designed according to the respective material’s properties. There are two broad categories of the materials available from Carbon 3D, prototyping resins, and engineering resins. While the prototyping resin is used for the cosmetic models and the engineering resins are used for the practical applications. There are 6 types of engineering resins developed for the end user; of these, EPU and CE are more challenging to work with. EPU parts needs more supports and careful handling till the completion of post processing as the material is soft. CE parts are fragile and needs more systematic handling to complete the successful production. Although printing parts of EPU and CE is more time consuming when compared to the normal CLIP process, they are worth for their unmatched industrial applications. None of the existing 3D printing technologies offers this quality. The support structure, orientation and pot life are the influencing parameters for all resins. In this study, it is statistically proven that by optimizing the part orientation with respect to the slicing of each layer and customized supports; parts are built way better than before. The part orientation is optimized by ensuring each layer is supporting the subsequent layer and minimizing the islands. It is noticed that the results are always better by tilting the part 5 to 10 degrees in both X and Y axis in the build setup and this applies for most of the straight geometrical parts. For parts of specific geometry which can create a vacuum while pulling up the part needs to be oriented in a different way or create a re-closable air passage that can prevent the vacuum being created.

scholarly journals Optimization of Friction Welding Process Parameters for 42Cr9Si2 Hollow Head and Sodium Filled Engine Valve and Valve Performance Evaluation

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1123
Author(s):  
Fuqiang Lai ◽  
Shengguan Qu ◽  
Roger Lewis ◽  
Tom Slatter ◽  
Ge Sun ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Friction Welding ◽  
Elevated Temperatures ◽  
Welding Process ◽  
Process Parameter ◽  
Superior Performance ◽  
Welding Parameters ◽  
Manufacturing Method ◽  
Rotating Bending Fatigue ◽  
And Performance

Due to their design, hollow cavity and filled sodium, hollow head and sodium filled engine valves (HHSVs) have superior performance to traditional solid valves in terms of mass and temperature reduction. This paper presents a new manufacturing method for 42Cr9Si2 steel hollow head and sodium filled valves. An inertia friction welding process parameter optimization was conducted to obtain a suitable process parameter range. The fatigue strength of 42Cr9Si2 steel at elevated temperatures was evaluated by rotating bending fatigue test with material specimens. Performance evaluation tests for real valve components were then carried out using a bespoke bench-top apparatus, as well as a stress evaluation utilizing a finite element method. It was proved that the optimized friction welding parameters of HHSV can achieve good welding quality and performance, and the HHSV specimen successfully survived defined durability tests proving the viability of this new method. The wear resistance of the HHSV specimens was evaluated and the corresponding wear mechanisms were found to be those classically defined in automotive valve wear.

scholarly journals Fabrication of Demineralized Bone Matrix/Polycaprolactone Composites Using Large Area Projection Sintering (LAPS)

2019 ◽  
Vol 3 (2) ◽  
pp. 30 ◽  
Author(s):  
Mohsen Ziaee ◽  
Rebecca Hershman ◽  
Ayesha Mahmood ◽  
Nathan B. Crane
Keyword(s):  
Additive Manufacturing ◽  
Cancellous Bone ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Bone Allograft ◽  
Layer By Layer ◽  
Large Area ◽  
Manufacturing Method ◽  
Synthetic Scaffolds ◽  
Demineralized Bone

Cadaveric decellularized bone tissue is utilized as an allograft in many musculoskeletal surgical procedures. Typically, the allograft acts as a scaffold to guide tissue regeneration with superior biocompatibility relative to synthetic scaffolds. Traditionally these scaffolds are machined into the required dimensions and shapes. However, the geometrical simplicity and, in some cases, limited dimensions of the donated tissue restrict the use of allograft scaffolds. This could be overcome by additive manufacturing using granulated bone that is both decellularized and demineralized. In this study, the large area projection sintering (LAPS) method is evaluated as a fabrication method to build porous structures composed of granulated cortical bone bound by polycaprolactone (PCL). This additive manufacturing method utilizes visible light to selectively cure the deposited material layer-by-layer to create 3D geometry. First, the spreading behavior of the composite mixtures is evaluated and the conditions to attain improved powder bed density to fabricate the test specimens are determined. The tensile strength of the LAPS fabricated samples in both dry and hydrated states are determined and compared to the demineralized cancellous bone allograft and the heat treated demineralized-bone/PCL mixture in mold. The results indicated that the projection sintered composites of 45–55 wt %. Demineralized bone matrix (DBM) particulates produced strength comparable to processed and demineralized cancellous bone.

Experimental Investigation of Selective Laser Melting of Lunar Regolith for In-Situ Applications

2013 ◽  
Author(s):  
Miranda Fateri ◽  
Andreas Gebhardt ◽  
Maziar Khosravi
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Lunar Regolith ◽  
Laser Melting ◽  
Manufacturing Method ◽  
3D Objects ◽  
Scan Speed ◽  
Manufacturing Methods ◽  
Object Layer

Selective Laser Melting (SLM) is a powder based Additive manufacturing (AM) technology which builds an object layer wise using a laser beam to melt the powder on an elevated platform. Thus far numerous studies have investigated lunar manufacturing methods and construction but little is known about applicability of SLM of lunar regolith. As most lunar construction proposals require transportation of essential materials from Earth, using an in-situ manufacturing method with indigenous material would be considerably more economical. Fabrication of parts with SLM using various metals and ceramics has already been presented. As such, the feasibility of using lunar regolith mixture to create functional parts with SLM process is investigated. Variation of process parameters such as laser power, scan speed, and scan strategies is investigated and multiple 3D objects are successfully created and presented.

Design and NC Manufacturing of Plastic Injection Mold Based on UG Software

2012 ◽  
Vol 630 ◽  
pp. 163-166
Author(s):  
Shan Li ◽  
Liang Xu ◽  
Yu Qi Wang
Keyword(s):  
Traditional Method ◽  
Injection Mold ◽  
Practical Application ◽  
Manufacturing Method ◽  
Whole Process ◽  
Traditional Design ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
Plastic Injection

On the platform of the UG Software’s CAD/MoldWizard/CAM components, the whole process of design and NC manufacturing of the plastic injection mold of a hair dryer’s shell was completed. The CAD/CAM process of the plastic injection mold was introduced by the practical application. The large advantage of the UG platform over the traditional method in the field of plastic injection molds’ design and manufacturing was reflected. The plastic injection molds’ design and manufacturing is a great challenge to the traditional design and manufacturing method, and the UG solutions can promote mold manufacturers’ ability of design and manufacturing remarkably.

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