scholarly journals Optimization of AZ91D Process and Corrosion Resistance Using Wire Arc Additive Manufacturing

2018 ◽  
Vol 8 (8) ◽  
pp. 1306 ◽  
Author(s):  
Seungkyu Han ◽  
Matthew Zielewski ◽  
David Martinez Holguin ◽  
Monica Michel Parra ◽  
Namsoo Kim
Keyword(s):  
Corrosion Resistance ◽  
Additive Manufacturing ◽  
Human Body ◽  
Structural Integrity ◽  
Material Selection ◽  
Essential Element ◽  
The Body ◽  
Corrosion Rates ◽  
Wire Arc Additive Manufacturing

Progress on Additive Manufacturing (AM) techniques focusing on ceramics and polymers evolves, as metals continue to be a challenging material to manipulate when fabricating products. Current methods, such as Selective Laser Sintering (SLS) and Electron Beam Melting (EBM), face many intrinsic limitations due to the nature of their processes. Material selection, elevated cost, and low deposition rates are some of the barriers to consider when one of these methods is to be used for the fabrication of engineering products. The research presented demonstrates the use of a Wire and Arc Additive Manufacturing (WAAM) system for the creation of metallic specimens. This project explored the feasibility of fabricating elements made from magnesium alloys with the potential to be used in biomedical applications. It is known that the elastic modulus of magnesium closely approximates that of natural bone than other metals. Thus, stress shielding phenomena can be reduced. Furthermore, the decomposition of magnesium shows no harm inside the human body since it is an essential element in the body and its decomposition products can be easily excreted through the urine. By alloying magnesium with aluminum and zinc, or rare earths such as yttrium, neodymium, cerium, and dysprosium, the structural integrity of specimens inside the human body can be assured. However, the in vivo corrosion rates of these products can be accelerated by the presence of impurities, voids, or segregation created during the manufacturing process. Fast corrosion rates would produce improper healing, which, in turn, involve subsequent surgical intervention. However, in this study, it has been proven that magnesium alloy AZ91D produced by WAAM has higher corrosion resistance than the cast AZ91D. Due to its structure, which has porosity or cracking only at the surface of the individual printed lines, the central sections present a void-less structure composed by an HCP magnesium matrix and a high density of well dispersed aluminum-zinc rich precipitates. Also, specimens created under different conditions have been analyzed in the macroscale and microscale to determine the parameters that yield the best visual and microstructural results.

scholarly journals Wire Arc Additive Manufacturing: Review on Recent Findings and Challenges in Industrial Applications and Materials Characterization

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 939
Author(s):  
Mukti Chaturvedi ◽  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Luigi Renato Mistodie ◽  
Danut Mihailescu ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Integrity ◽  
Industrial Applications ◽  
Raw Material ◽  
Continuous Increase ◽  
Control Optimization ◽  
Modern Manufacturing ◽  
Directed Energy ◽  
Manufacturing Technologies ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is a fusion manufacturing process in which the heat energy of an electric arc is employed for melting the electrodes and depositing material layers for wall formation or for simultaneously cladding two materials in order to form a composite structure. This directed energy deposition-arc (DED-arc) method is advantageous and efficient as it produces large parts with structural integrity due to the high deposition rates, reduced wastage of raw material, and low consumption of energy in comparison with the conventional joining processes and other additive manufacturing technologies. These features have resulted in a constant and continuous increase in interest in this modern manufacturing technique which demands further studies to promote new industrial applications. The high demand for WAAM in aerospace, automobile, nuclear, moulds, and dies industries demonstrates compatibility and reflects comprehensiveness. This paper presents a comprehensive review on the evolution, development, and state of the art of WAAM for non-ferrous materials. Key research observations and inferences from the literature reports regarding the WAAM applications, methods employed, process parameter control, optimization and process limitations, as well as mechanical and metallurgical behavior of materials have been analyzed and synthetically discussed in this paper. Information concerning constraints and enhancements of the wire arc additive manufacturing processes to be considered in terms of wider industrial applicability is also presented in the last part of this paper.

Microstructure and Corrosion Resistance of Ni-Cu Alloy Fabricated through Wire Arc Additive Manufacturing

2021 ◽  
pp. 131262
Author(s):  
A. Rajesh Kannan ◽  
S. Mohan Kumar ◽  
R. Pramod ◽  
N. Siva Shanmugam ◽  
M. Vishnukumar ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Additive Manufacturing ◽  
Cu Alloy ◽  
Wire Arc Additive Manufacturing

scholarly journals Environmental Behavior of Low Carbon Steel Produced by a Wire Arc Additive Manufacturing Process

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 888 ◽  
Author(s):  
Ron ◽  
Levy ◽  
Dolev ◽  
Leon ◽  
Shirizly ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Additive Manufacturing ◽  
Carbon Steel ◽  
Stress Corrosion ◽  
Environmental Behavior ◽  
Low Carbon Steel ◽  
General Corrosion ◽  
Low Carbon ◽  
Corrosion Performance ◽  
Wire Arc Additive Manufacturing

: Current additive manufacturing (AM) processes are mainly focused on powder bed technologies, such as electron beam melting (EBM) and selective laser melting (SLM). However, the main disadvantages of such techniques are related to the high cost of metal powder, the degree of energy consumption, and the sizes of the components, that are limited by the size of the printing cell. The aim of the present study was to evaluate the environmental behavior of low carbon steel (ER70S-6) produced by a relatively inexpensive AM process using wire feed arc welding. The mechanical properties were examined by tension testing and hardness measurements, while microstructure was assessed by scanning electron microscopy and X-ray diffraction analysis. General corrosion performance was evaluated by salt spray testing, immersion testing, potentiodynamic polarization analysis, and electrochemical impedance spectroscopy. Stress corrosion performance was characterized in terms of slow strain rate testing (SSRT). All corrosion tests were carried out in 3.5% NaCl solution at room temperature. The results indicated that the general corrosion resistance of wire arc additive manufacturing (WAAM) samples were quite similar to those of the counterpart ST-37 steel and the stress corrosion resistance of both alloys was adequate. Altogether, it was clearly evident that the WAAM process did not encounter any deterioration in corrosion performance compared to its conventional wrought alloy counterpart.

scholarly journals Residual Stress and Microstructure of a Ti-6Al-4V Wire Arc Additive Manufacturing Hybrid Demonstrator

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 701
Author(s):  
Tatiana Mishurova ◽  
Benjamin Sydow ◽  
Tobias Thiede ◽  
Irina Sizova ◽  
Alexander Ulbricht ◽  
...  
Keyword(s):  
Residual Stress ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Hybrid Approach ◽  
Aerospace Applications ◽  
Machined Parts ◽  
Functional Features ◽  
Tool Set ◽  
Wire Arc Additive Manufacturing

Wire Arc Additive Manufacturing (WAAM) features high deposition rates and, thus, allows production of large components that are relevant for aerospace applications. However, a lot of aerospace parts are currently produced by forging or machining alone to ensure fast production and to obtain good mechanical properties; the use of these conventional process routes causes high tooling and material costs. A hybrid approach (a combination of forging and WAAM) allows making production more efficient. In this fashion, further structural or functional features can be built in any direction without using additional tools for every part. By using a combination of forging basic geometries with one tool set and adding the functional features by means of WAAM, the tool costs and material waste can be reduced compared to either completely forged or machined parts. One of the factors influencing the structural integrity of additively manufactured parts are (high) residual stresses, generated during the build process. In this study, the triaxial residual stress profiles in a hybrid WAAM part are reported, as determined by neutron diffraction. The analysis is complemented by microstructural investigations, showing a gradient of microstructure (shape and size of grains) along the part height. The highest residual stresses were found in the transition zone (between WAAM and forged part). The total stress range showed to be lower than expected for WAAM components. This could be explained by the thermal history of the component.

Dynamic ease evaluation for 3D garment design

2018 ◽  
Vol 22 (2) ◽  
pp. 209-222
Author(s):  
Fangfang Zhang ◽  
Trevor John Little
Keyword(s):  
Human Body ◽  
Design Methodology ◽  
Human Subjects ◽  
Essential Element ◽  
The Body ◽  
Upper Arm ◽  
Core Element ◽  
Content Type ◽  
Comfort Evaluation ◽  
Garment Design

Purpose 3D garment design technology is developing rapidly thereby creating a need for different approaches to developing the patterns. The purpose of this paper is to evaluate the 3D dynamic ease distribution for a 3D garment design. Design/methodology/approach Standard garments were created from Size 2 to Size 14 for ten human subjects. Landmarks location on both human body and the standard garment under dynamic postures are recorded, and he fit and comfort evaluation of the standard garment were collected from the ten human subjects. Finally, these data were used to evaluate the 3D dynamic ease distribution for a 3D garment design. Findings 3D dynamic ease evaluation is challenging and the findings showed that the upper-arm design is a core element of the whole 3D garment design. The upper arm is not only a connecting part for both front and back pieces of the garment, but is also the main active part of the body, so it is the essential element to affect the comfort and fit of the garment under dynamic postures. Originality/value This research provides a novel 3D ease evaluation by analyzing the landmarks location of both human body and standard garment, and fit and comfort evaluation of the standard garment, which are all carried under dynamic postures.

scholarly journals Localized Corrosion Resistance on Additively Manufactured Ti Alloys by Means of Electrochemical Critical Localized Corrosion Potential in Biomedical Solution Environments

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7481
Author(s):  
Dong-Il Seo ◽  
Jae-Bong Lee
Keyword(s):  
Corrosion Resistance ◽  
Additive Manufacturing ◽  
Passive Film ◽  
Human Body ◽  
Corrosion Potential ◽  
New Method ◽  
Localized Corrosion ◽  
Ti Alloys ◽  
Corrosive Environments ◽  
Repassivation Kinetics

This study proposes a new method, electrochemical critical localized corrosion potential (E-CLCP), in order to evaluate localized corrosion resistance of biomedical additive manufacturing (AM) titanium (Ti) alloys. The procedures for determining E-CLCP are completely different from that of the electrochemical critically localized corrosion temperature (E-CLCT) method (ISO 22910:2020). However, its application should be limited to pH and temperature of the human body because of the temperature scan. E-CLCP displays the localized corrosion resistance of AM Ti alloys based on the human body’s repassivation kinetics, whereas E-CLCT displays the localized corrosion resistance of the alloys based on passive film breakdown in much harsher corrosive environments.

The Influence of Heat Treatment and Plastic Deformation on the Bio-Degradation of a Mg–Y–RE Alloy

2009 ◽  
Vol 618-619 ◽  
pp. 71-74 ◽  
Author(s):  
Petra Gunde ◽  
Angela Furrer ◽  
Anja C. Hänzi ◽  
Patrik Schmutz ◽  
Peter J. Uggowitzer
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Oxide Layer ◽  
Human Body ◽  
Electrochemical Impedance ◽  
Essential Element ◽  
Heat Treatments ◽  
Protective Oxide ◽  
Degradation Behaviour ◽  
Polarisation Resistance

Magnesium has become an interesting candidate in the field of bioabsorbable implant materials; it is an essential element in the human body, biocompatible and degradable due to its low corrosion resistance in a pH range below 11.5. However, in the human body (pH  7.4) a magnesium implant might degrade too quickly and lose its mechanical strength before the tissue has fully healed. However, the corrosion resistance can be improved for example by the choice of a suitable Mg alloy containing corrosion-inhibiting elements such as yttrium or by the deployment of surface heat treatments at high temperatures causing protective oxide layers to form. We studied the bio-degradation behaviour of a Mg–Y–RE alloy in different heat treatment states by electrochemical impedance spectroscopy and immersion testing in simulated body fluid. The heat treatments caused a change in microstructure and also the formation of a thermal oxide layer on the sample surface, which consisted mainly of Y2O3 and which slowed the degradation and increased the polarisation resistance significantly compared to the polished state. However, in some specimens localised corrosion attacks occurred which drastically weakened the protective effect of the oxide. Because the implant might be deformed during implantation resulting in the oxide cracking, we intentionally strained the samples and investigated the degradation performance. These cracks led to a decrease in polarisation resistance compared to the non-strained oxidised state, but in comparison to the polished state they still perform better. Macroscopically, the degradation process occurred in a homogeneous way without localised corrosion attacks. Microscopically, corrosion attacks started at the cracks and undermined the oxide layer with time.

Surface Modification of Magnesium with Rare Earth Conversion Films for Biomedical Protection

2007 ◽  
Vol 546-549 ◽  
pp. 601-604 ◽  
Author(s):  
Jia Cheng Gao ◽  
Yan Xue ◽  
Li Ying Qiao ◽  
Yong Wang ◽  
Yan Zhang
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Metabolic Process ◽  
The Body ◽  
Surface Microstructure ◽  
Corrosion Properties ◽  
Corrosion Rates ◽  
Protective Films ◽  
Relationship Of ◽  
The Relationship

The specific gravity and elastic modulus of magnesium alloys are similar to that of human bone. Magnesium is one of the most important elements in the human body and plays a key role in the metabolic process. But the application of magnesium is seriously limited as a biomaterial since it corrodes easily in the physiological environment of the body. In order to reduce the corrosion, we developed protective films using rare earth (RE) conversion processing. The surface of magnesium samples was modified by contact with different rare-earth salt solutions; then the samples were dipped in SBF to test their corrosion resistance. The change of mass and the pH of the solutions were measured continuously using an electronic scale and a pH micrometer. The surface microstructure of the samples was observed by XRD and metallomicroscope. Corrosion rates of the samples in SBF were determined using Taffier curve. The preliminary results show that the conversion treatment with CeCl3 or Y(NO3)3 can improve the corrosion resistance of magnesium in SBF. The relationship of the RE salts concentration and the corrosion properties were studied,the best combination of parameters was determined, and the formation mechanism of rare-earth conversion film has been also elaborated.

scholarly journals A pilot study on the use of 3D printers in veterinary medicine

2021 ◽  
Vol 14 (3) ◽  
pp. 159-164
Author(s):  
Leonardo Leonardi ◽  
◽  
Roberto Marsili ◽  
Enrico Bellezza ◽  
Giovanni Angeli ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Bone Tissue ◽  
Three Dimensional ◽  
The Body ◽  
Porous Scaffolds ◽  
Layer By Layer ◽  
Three Dimensional Objects ◽  
Cellular Attachment

Additive manufacturing (AM) is the process of joining materials to create layer-by-layer three-dimensional objects using a 3D printer from a digital model. The great advantage of Additive Manufacturing is to allow a freer design than traditional processes. The development of additive manufacturing processes has permitted to optimize the production of the customized product through the modeling of the geometry and the knowledge of the morphometric parameters of the body structures. 3D printing has revolutionized the field of Regenerative Medicine because, starting from computerized tomography (CT) images and using traditional materials such as plastic and metals, it can provide customized prostheses for each patient, which adapt perfectly to the needs of the subject and act as structures support. 3D printing allows you to print three-dimensional porous scaffolds with a precise shape and chemical composition suitable for medical and veterinary use. Some of these scaffolds are biodegradable and appear to be ideal for bone tissue engineering. In fact, they are able to simulate extracellular matrix properties that allow mechanical support, favoring mechanical interactions and providing a model for cellular attachment and in vivo stimulation of bone tissue formation.

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