Fast Computation of Thermal Field of Direct Metal Deposition: A Preliminary Study Based on Quiet Element Method

2018 ◽  
Author(s):  
Jin Wang ◽  
Jing Shi ◽  
Yi Wang ◽  
Yuli Hu ◽  
Jun Dai ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Thermal Field ◽  
High Energy ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Convergence Criterion ◽  
Fast Computation ◽  
Commercial Software ◽  
Element Analysis ◽  
Element Method

Direct metal deposition (DMD) is a major additive manufacturing (AM) process, which employs high energy beams as the heat source to melt and deposit metals in layerwise fashion so that complex structural components can be directly obtained. Similar to other metal AM processes, DMD is a complicated thermo-mechanical process, characterized by fast scan rates, large thermal gradients, rapid material phase transformations, and cyclic non-uniform temperature changes. Accurate and efficient computation of the thermal field during the DMD process is essential for understanding the fundamental microstructure evolution and developing the optimization strategy. In this paper, we aim to develop an open-source and fast computation tool for analyzing the heat transfer during the DMD process, which is based on the finite volume formulation and the quiet element method and allows development of customized functionalities at the source level. A computing tool is developed in MATLAB for fast prediction of the temperature field during metal additive manufacturing, and compared against the regular finite element analysis using a commercial software. The preliminary results show that for a system of 14400 cells, deposition of a single path takes 174 s using the commercial software, and 15.8s to 81s depending on the setting of convergence criterion using the in-house code. This represents a time reduction ranged from 90.9% to 53.4%, and the overall error is around 12.1%.

Advances in Direct Metal Deposition

2013 ◽  
Author(s):  
Jyoti Mazumder ◽  
Lijun Song
Keyword(s):  
Additive Manufacturing ◽  
Optical Sensors ◽  
Thermal Cycle ◽  
Industrial Revolution ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Layer By Layer ◽  
Enabling Technology ◽  
Economic Space ◽  
Line Process

Recently Additive Manufacturing (AM) has been hailed as the “third industrial revolution” by The Economist magazine [April-2012]. Precision of the product manufactured by AM largely depends on the on line process diagnostics and control. AM caters to the quest for a material to suit the service performance, which is almost as old as the human civilization. An enabling technology which can build, repair or reconfigure components layer by layer or even pixel by pixel with appropriate materials to match the performance will enhance the productivity and thus reduce energy consumption. With the globalization, “Economic Space” for an organization is now spreads all across the globe. The promise of AM for Global Platform for precision additive manufacturing largely depends on the speed and accuracy of in-situ optical diagnostics and its capability to integrate with the process control. The two main groups of AM are powder bed (e.g. Laser Sintering) and pneumatically delivered powder (e.g. Direct Metal Deposition [DMD]) to fabricate components. DMD has closed loop capability, which enables better dimension and thermal cycle control. This enables one to deposit different material at different pixels with a given height directly from a CAD drawing. The feed back loop also controls the thermal cycle. New optical Sensors are either developed or being developed to control geometry using imaging, cooling rate by monitoring temperature, microstructure, temperature and composition using optical spectra. Ultimately these sensors will enable one to “Certify as you Build”. Flexibility of the process is enormous and essentially it is an enabling technology to materialize many a design. Several cases will be discussed to demonstrate the additional capabilities possible with the new sensors. Conceptually one can seat in Singapore and fabricate in Shanghai. Such systems will be a natural choice for a Global “Economic Space”.

Thermal Analysis and Verification for Direct Metal Deposition of 0Cr18Ni9 Stainless Steel

2019 ◽  
Author(s):  
Jin Wang ◽  
Jing Shi ◽  
Yi Wang ◽  
Yun Bai
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Process Parameters ◽  
Thermal Stresses ◽  
Infrared Camera ◽  
Dimensional Accuracy ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Heating And Cooling

Abstract Due to rapid cyclic heating and cooling in metal additive manufacturing processes, such as selective laser melting (SLM) and direct metal deposition (DMD), large thermal stresses will form and this may lead to the loss of dimensional accuracy or even cracks. The integration of numerical analysis and experimental validation provides a powerful tool that allows the prediction of defects, and optimization of the component design and the additive manufacturing process parameters. In this work, a numerical simulation on the thermal process of DMD of 0Cr18Ni9 stainless steel is conducted. The simulation is based on the finite volume method (FVM). An in-house code is developed, and it is able to calculate the temperature distribution dynamically. The model size is 30mm × 30mm × 10.5mm, containing 432,000 cells. A DMD experiment on the material with the same configuration and process parameters is also carried out, during which an infrared camera is adopted to obtain the surface temperature distribution continuously, and thermocouples are embedded in the baseplate to record the temperature histories. It is found that the numerical results agree with the experimental results well.

Precision additive manufacturing of NiTi parts using micro direct metal deposition

2018 ◽  
Vol 96 (9-12) ◽  
pp. 3729-3736 ◽  
Author(s):  
Saeed Khademzadeh ◽  
Filippo Zanini ◽  
Paolo F. Bariani ◽  
Simone Carmignato
Keyword(s):  
Additive Manufacturing ◽  
Metal Deposition ◽  
Direct Metal Deposition

scholarly journals Numerical simulation and experimental calibration of additive manufacturing by blown powder technology. Part I: thermal analysis

2017 ◽  
Vol 23 (2) ◽  
pp. 448-463 ◽  
Author(s):  
Michele Chiumenti ◽  
Xin Lin ◽  
Miguel Cervera ◽  
Wei Lei ◽  
Yuxiang Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Numerical Model ◽  
High Energy ◽  
Metal Deposition ◽  
Numerical Control ◽  
Experimental Calibration ◽  
Standard Format ◽  
Content Type ◽  
Scanning Pattern

Purpose This paper aims to address the numerical simulation of additive manufacturing (AM) processes. The numerical results are compared with the experimental campaign carried out at State Key Laboratory of Solidification Processing laboratories, where a laser solid forming machine, also referred to as laser engineered net shaping, is used to fabricate metal parts directly from computer-aided design models. Ti-6Al-4V metal powder is injected into the molten pool created by a focused, high-energy laser beam and a layer of added material is sinterized according to the laser scanning pattern specified by the user. Design/methodology/approach The numerical model adopts an apropos finite element (FE) activation technology, which reproduces the same scanning pattern set for the numerical control system of the AM machine. This consists of a complex sequence of polylines, used to define the contour of the component, and hatches patterns to fill the inner section. The full sequence is given through the common layer interface format, a standard format for different manufacturing processes such as rapid prototyping, shape metal deposition or machining processes, among others. The result is a layer-by-layer metal deposition which can be used to build-up complex structures for components such as turbine blades, aircraft stiffeners, cooling systems or medical implants, among others. Findings Ad hoc FE framework for the numerical simulation of the AM process by metal deposition is introduced. Description of the calibration procedure adopted is presented. Originality/value The objectives of this paper are twofold: firstly, this work is intended to calibrate the software for the numerical simulation of the AM process, to achieve high accuracy. Secondly, the sensitivity of the numerical model to the process parameters and modeling data is analyzed.

Laser Cladding Based Solid Freeform Fabrication and Direct Metal Deposition

2006 ◽  
Author(s):  
Huan Qi ◽  
Jyotirmoy Mazumder
Keyword(s):  
Laser Beam ◽  
Laser Cladding ◽  
Solid Freeform Fabrication ◽  
Three Dimensional ◽  
High Energy ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Effective Control ◽  
Metal Powders ◽  
Freeform Fabrication

Three-dimensional additive manufacturing or solid freeform fabrication (SFF) techniques, originated in the rapid fabrication of non-functional physical prototypes in polymers (Rapid Prototyping), have matured to the manufacture of functional prototypes, short-run production products, and now even advanced engineering designs. Laser-based material deposition or laser cladding has been used as a SFF technique, in which a laser beam is used as a precise high-energy thermal source to melt preplaced or pneumatically delivered metal powders and make solidified deposits on a substrate. By using laser cladding techniques, three-dimensional fully dense components can be built line-by-line and layer-by-layer directly from a CAD model with tailored material properties. Laser cladding is essentially a fusion and solidification (thermal) process, which involves complicated interactions between the laser beam, metal powders, the base material (substrate), and processing gases. Maintaining a stable and uniform melt pool during laser cladding is critical to produce dimensional accuracy and material integrity. An effective control of energy (laser power) spatial and temporal distributions in either an open-loop or closed-loop laser cladding process is essential to achieve the high quality results. This paper reviews, from a laser-material interaction point of view, various laser cladding based SFF processes, and particularly the direct metal deposition technique.

scholarly journals Present of Three-layered hydro-forming analysis of a new hybrid sandwich tubes using finite element method

2012 ◽  
pp. 208-215
Author(s):  
J. Shahbazi Karami ◽  
G. Payganeh ◽  
K. Malekzadeh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bending Strength ◽  
Middle Layer ◽  
High Energy ◽  
Experimental Result ◽  
Element Analysis ◽  
Forming Analysis ◽  
Tube Hydro Forming ◽  
Element Method

Multi-layered tube hydro-forming is suitable to produce multi-layered joints to be used in special application in many industries. With using a middle layer of foam and making sandwich structures, tube bending strength increases when external loads are applied. Also because of the foam is high energy absorption, in the pipelines of major industries such as the nuclear, strength increases when natural disasters, especially earthquakes happen. In this paper for the first time, three-layered new sandwich tube (inner layer of copper, middle layer of aluminum foam and outer layer of annealed brass) hydroforming processes were numerically simulated using finite element method by ABAQUS/Explicit 6.10. As the result of three-layered sandwich tube hydro-forming not reported in the literature, the results of this paper are compared with the latest experimental result of bi-layered tube hydro-forming find in literature by approaching the thickness of middle layer to zero. Finite element analysis shows that numerical and experimental results have a good agreement

An Experimental Characterization of Powder/Substrate Interaction during Direct Metal Deposition for Additive Manufacturing

2019 ◽  
Vol 813 ◽  
pp. 435-440
Author(s):  
Maurizio Troiano ◽  
Alessia Teresa Silvestri ◽  
Fabio Scherillo ◽  
Andrea El Hassanin ◽  
Roberto Solimene ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Surface Morphology ◽  
Laser Power ◽  
Surface Characterization ◽  
Spot Size ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Metal Powders ◽  
Substrate Interaction

The physical behavior of metal powders during laser-based additive manufacturing processes has been investigated. In particular, an experimental campaign of direct metal deposition has been carried out to evaluate the effect of the laser power and spot size on the powder/substrate interaction and on the surface morphology of the final piece. A fast-camera has been used to evaluate the interaction phenomena during the printing process, while confocal microscopy has been carried out to measure the surface morphology of the samples. Results highlighted that increasing the laser power and laser spot size, the particle impact velocity is about constant, while the powder/laser/substrate interaction zone increases. As a consequence, the mean thickness increases, as confirmed by surface characterization.

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