scholarly journals An Example of Controlling the Obtained Characteristics of Technological Stress Distributions in a Layer-By-Layer Manufactured Product, Based on a Model of Additive Process Mechanics

2021 ◽  
Vol 1079 (5) ◽  
pp. 052049
Author(s):  
D A Parshin
Keyword(s):  
Layer By Layer ◽  
Stress Distributions ◽  
Additive Process ◽  
Process Mechanics ◽  
Technological Stress

Evolution of Direct Selective Laser Sintering of Metals

2011 ◽  
Vol 383-390 ◽  
pp. 6252-6257
Author(s):  
Francesco Cardaropoli ◽  
Fabrizia Caiazzo ◽  
Vincenzo Sergi
Keyword(s):  
Complex Geometry ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Layer By Layer ◽  
Metal Powders ◽  
Additive Process ◽  
Operator Experience ◽  
Critical Phases ◽  
Time Required

Direct Metal Selective Laser Sintering (DMSLS) is a layer-by-layer additive process for metal powders, which allows quick production of complex geometry parts. The aim of this study is to analyse the improvement of DMSLS with “EOSINT M270”, the new laser sintering machine developed by EOS. Tests were made on sintered parts of Direct Metal 20 (DM20), a bronze based powder with a mean grain dimension of 20 μm. Different properties and accuracy were evaluated for samples manufactured with three different exposure strategies. Besides mechanical properties, the manufacturing process was also examined in order to evaluate its characteristics. The quality of laser sintered parts is too affected by operator experience and skill. Furthermore, critical phases are not automatic and this causes an extension of time required for the production. Due to these limitations, DMSLS can be used for Rapid Manufacturing, but it is especially suitable to few sample series.

Spatial Iterative Learning Control for Multi-material Three-Dimensional Structures

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Zahra Afkhami ◽  
Christopher Pannier ◽  
Leontine Aarnoudse ◽  
David Hoelzle ◽  
Kira Barton
Keyword(s):  
Additive Manufacturing ◽  
Iterative Learning Control ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Single Layer ◽  
Learning Control ◽  
Iterative Learning ◽  
Layer By Layer ◽  
Additive Process ◽  
Jet Printing

Abstract Iterative learning control (ILC) is a powerful technique to regulate repetitive systems. Additive manufacturing falls into this category by nature of its repetitive action in building three-dimensional structures in a layer-by-layer manner. In literature, spatial ILC (SILC) has been used in conjunction with additive processes to regulate single-layer structures with only one class of material. However, SILC has the unexplored potential to regulate additive manufacturing structures with multiple build materials in a three-dimensional fashion. Estimating the appropriate feedforward signal in these structures can be challenging due to iteration varying initial conditions, system parameters, and surface interaction dynamics in different layers of multi-material structures. In this paper, SILC is used as a recursive control strategy to iteratively construct the feedforward signal to improve part quality of 3D structures that consist of at least two materials in a layer-by-layer manner. The system dynamics are approximated by discrete 2D spatial convolution using kernels that incorporate in-layer and layer-to-layer variations. We leverage the existing SILC models in literature and extend them to account for the iteration varying uncertainties in the plant model to capture a more reliable representation of the multi-material additive process. The feasibility of the proposed diagonal framework was demonstrated using simulation results of an electrohydrodynamic jet printing (e-jet) printing process.

Additive Manufacturing

2019 ◽  
pp. 165-183 ◽  
Author(s):  
Kamardeen Olajide Abdulrahman ◽  
Esther T. Akinlabi ◽  
Rasheedat M. Mahamood
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Titanium Aluminide ◽  
Three Dimensional ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Additive Process

Three-dimensional printing has evolved into an advanced laser additive manufacturing (AM) process with capacity of directly producing parts through CAD model. AM technology parts are fabricated through layer by layer build-up additive process. AM technology cuts down material wastage, reduces buy-to-fly ratio, fabricates complex parts, and repairs damaged old functional components. Titanium aluminide alloys fall under the group of intermetallic compounds known for high temperature applications and display of superior physical and mechanical properties, which made them most sort after in the aeronautic, energy, and automobile industries. Laser metal deposition is an AM process used in the repair and fabrication of solid components but sometimes associated with thermal induced stresses which sometimes led to cracks in deposited parts. This chapter looks at some AM processes with more emphasis on laser metal deposition technique, effect of LMD processing parameters, and preheating of substrate on the physical, microstructural, and mechanical properties of components produced through AM process.

ADDITIVE DIGITAL TECHNOLOGIES FOR FORMING METASUBJECT LEARNING OUTCOMES

2020 ◽  
pp. 49-58 ◽  
Author(s):  
O. S. Samaeva ◽  
S. O. Astashkin
Keyword(s):  
General Education ◽  
Learning Outcomes ◽  
Research Work ◽  
Federal State ◽  
3D Printer ◽  
Layer By Layer ◽  
Educational Standards ◽  
School Students ◽  
Additive Process ◽  
State Educational

According the requirements of the new Federal State Educational Standards of General Education, the article examines the experience of generating metasubject learning outcomes at informatics lessons by the example of performing by technical school students the project and research work to study 3D modeling, 3D printing and additive technologies. The stages of the project are described in detail: study of the theory of the additive process of layer-by-layer model creation; development in the SolidWorks system of the graphic part of the work on creating a prototype; printing of a prototype on a 3D printer; making calculations to justify the benefits of using a 3D prototype; checking the performance of the finished product, the possibility of its use in laboratory and educational purposes; developing recommendations for working with a 3D printer.

Structure and Mechanical Properties of AlSi10Mg Fabricated by Selective Laser Melting Additive Manufacturing (SLM-AM)

2015 ◽  
Vol 1111 ◽  
pp. 62-66 ◽  
Author(s):  
Idan Rosenthal ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nachum Frage
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Electron Beam Welding ◽  
Rapid Progression ◽  
Thermal Gradients ◽  
Layer By Layer ◽  
Laser Melting ◽  
Additive Process ◽  
Building Products ◽  
Metallurgical Investigation

Additive manufacturing (AM) of metals is a relatively novel fabrication approach with growing interests in many industries. The AM process is based on building products originating from 3-D computer models, through localized melting of powder in a layered structure. The present research focused on the metallurgical investigation of AM AlSi10Mg parts fabricated by SLM-AM. The macrostructure of the product is a collage of solidified track segments, which were remelted several times by the adjacent neighboring tracks. The microstructure consists of fine cellular dendrites, which reflect high thermal gradients and rapid progression of the scanning laser during the AM process. The building strategy is crucial for the successful layer by layer additive process and the properties of the components. It was established that AM products yield higher mechanical properties than that for the parts fabricated by casting. Feasibility of AM parts joining by Electron Beam Welding (EBW) method is discussed.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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