scholarly journals CMT-Based Wire Arc Additive Manufacturing Using 316L Stainless Steel: Effect of Heat Accumulation on the Multi-Layer Deposits

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 278 ◽  
Author(s):  
Seung Hwan Lee
Keyword(s):  
Additive Manufacturing ◽  
Numerical Model ◽  
Heat Source ◽  
Cooling Rate ◽  
High Speed ◽  
Numerical Study ◽  
Transient Behavior ◽  
Heat Accumulation ◽  
Cmt Welding ◽  
Wire Arc Additive Manufacturing

CMT welding sources are garnering attention as alternative heat sources for wire arc additive manufacturing because of their low-heat input. A comprehensive experimental and numerical study on the multi-layer deposition of STS316L was performed to investigate effect of heat accumulation during the deposition. The numerical model which is appropriate for WAMM was developed considering the characteristics of the CMT heat source for the first time. Using a high-speed camera, the transient behavior of the CMT arc was investigated, and applied to the heat source of the numerical model. The model was then used to analyze 10-layered deposits of STS316L, fabricated using CMT-based WAAM. During deposition, the temperature is measured using a pyrometer to analyze the microstructure, after which the cooling rate of each layer is estimated. The measured and simulated SDAS were compared. Based on the comparison, a guideline for the equation regarding the SDAS size and cooling rate was suggested.

scholarly journals Effects of On-Line Vortex Cooling on the Microstructure and Mechanical Properties of Wire Arc Additively Manufactured Al-Mg Alloy

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1004 ◽  
Author(s):  
Baoxing Wang ◽  
Guang Yang ◽  
Siyu Zhou ◽  
Can Cui ◽  
Lanyun Qin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Cooling Rate ◽  
Low Cost ◽  
Heat Accumulation ◽  
Line Vortex ◽  
Microstructure And Mechanical Properties ◽  
Forming Precision ◽  
On Line ◽  
Wire Arc Additive Manufacturing

A novel on-line vortex cooling powered by low-cost compressed air was proposed to reduce common defects such as low forming precision, coarse grains, and pores caused by heat accumulation in the Wire Arc Additive Manufacturing (WAAM) of aluminum alloy. The impacts of interlayer cooling (IC), substrate cooling (SC), on-line cooling (OL), and natural cooling (NC) processes were compared on the morphology, microstructure, and mechanical properties of as-deposited walls, revealing that the OL process significantly lowers the interlayer temperature and improves forming precision. The high cooling rate produced by the OL process reduced the absorption of hydrogen in the molten pool, lowering porosity. Furthermore, the grains are refined due to the developed undercooling. However, the high cooling rate enhanced the segregation potential of Mg element and raised the content of the β phase. Conclusively, the maximum tensile strength, elongation, and microhardness of the as-deposited wall are achieved via the OL process, and the fine-grain strengthening mechanism plays an important role in improving mechanical properties. The OL process is cheaper and poses a significant effect; it is highly suitable for the additive manufacturing of complex components compared with other forced cooling processes.

scholarly journals Thermal analysis of Wire Arc Additive Manufacturing process

2021 ◽  
Author(s):  
Mohamed Belhadj ◽  
Sana Werda ◽  
Asma Belhadj ◽  
Robin Kromer ◽  
Philippe Darnis
Keyword(s):  
Additive Manufacturing ◽  
Numerical Model ◽  
Heat Source ◽  
Manufacturing Process ◽  
High Energy ◽  
Metal Deposition ◽  
Innovative Technology ◽  
Thermal Cycles ◽  
Predictive Tool ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing process (WAAM) is an innovative technology that offers freedom in terms of designing functional parts, due to its ability to manufacture large and complex workpieces with a high rate of deposition. This technology is a metal AM process using an electric arc heat source. The parts manufactured are affected by thermal residual stresses due to high-energy input between wire and workpiece despite numerous advantages with this technology. It could cause severe deformation and change the global mechanical response. A 3D transient thermal model was created to evaluate the thermal gradients and fields during metal deposition. The material used in this study is a steel alloy (S355JR-AR). This numerical model takes into account the heat dissipation through the external environment and the heat loss through the cooling system under the base plate. Birth-element activation strategy was used to generate warm solid part following the movement of the heat source. The metal deposition is defined with constant welding speed. Goldak model was used to simulate the heat source in order to have a realistic heat flow distribution. Results were in concordance for thermal cycles at different points comparing with experimental results issued from bibliography in terms of: (1) Temperature maximum, (2) Thermal cycles and (3) Cooling gradient phase. This study enabled to check the numerical model and used as a predictive tool

An experimental-numerical study of active cooling in wire arc additive manufacturing

2020 ◽  
Vol 52 ◽  
pp. 58-65 ◽  
Author(s):  
William Hackenhaar ◽  
José A.E. Mazzaferro ◽  
Filippo Montevecchi ◽  
Gianni Campatelli
Keyword(s):  
Additive Manufacturing ◽  
Numerical Study ◽  
Active Cooling ◽  
Wire Arc Additive Manufacturing

Analysis of combined radiation and convection heat transfer inside a porous medium with heat source electronic devices

2022 ◽  
pp. 095440622110467
Author(s):  
Ali Mokhtari Nahal ◽  
Mohammad Hassan Nobakhti ◽  
Cyrus Aghanajafi ◽  
Morteza Khayat
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Source ◽  
Cooling Rate ◽  
Numerical Study ◽  
Electronic Devices ◽  
Convection Heat Transfer ◽  
Darcy Number ◽  
Flow Lines ◽  
Rayleigh Numbers

In this study, a numerical study is performed on the cooling phenomenon of three heat source electronic devices. The electronic devices are cooled in the form of natural heat transfer by the airflow in a porous medium. Electronic devices are installed on the boundary walls of a square environment. Cooling simulations are performed by drawing flow lines and constant temperature lines. Our main goal is to find the highest cooling rate in different Darcy numbers and different Rayleigh numbers in our investigation. The range of Darcy numbers and Rayleigh numbers is between 0.0001 to 0.01 and 1000 to 100,000, respectively. Our investigation showed the maximum cooling is obtained at the Darcy number of about 0.01. And also, by decreasing the value of Darcy number, a higher cooling rate for the hot boundary walls is achieved.

Thermal Simulations for Cooling Rate Mapping in Electron Beam Additive Manufacturing

2015 ◽  
Author(s):  
Bo Cheng ◽  
Y. Kevin Chou
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Heat Source ◽  
Cooling Rate ◽  
Heat Transport ◽  
Process Parameters ◽  
Transport Process ◽  
Thermal Model ◽  
Heat Transport Process

The powder-bed electron beam additive manufacturing (EBAM) process is a relatively new AM technology that utilizes a high-energy heat source to fabricate metallic parts in a layer by layer fashion by melting metal powder in selected regions. EBAM can be able to produce full density part and complicated components such as near-net-shape parts for medical implants and internal channels. However, the large variation in mechanical properties of AM build parts is an important issue that impedes the mass production ability of AM technology. It is known that the cooling rate in the melt pool directly related to the build part microstructure, which greatly influences the mechanical properties such as strength and hardness. And the cooling rate is correlated to the basic heat transport process physics in EBAM, which includes a moving heat source and rapid self-cooling process. Therefore, a better understanding of the thermal process of the EBAM process is necessary. In this study, a 3D thermal model, using a finite element method (FEM), was utilized for EBAM heat transport process simulations. The process temperature prediction offers information of the cooling rate during the heating-cooling cycle. The thermal model is applied to evaluate, for the case of Ti-6Al-4V in EBAM, the process parameter effects, such as the beam speed and power, on the temperature profile along the melt scan and the corresponding cooling rate characteristics. The relationship between cooling rates and process parameters is systematically investigated, through multiple simulations, by incorporating different combinations of process parameters into the thermal model. The beam scanning speed vs. beam power curves of constant cooling rates can be obtained from 3D surface plots (cooling rate vs. different process parameters), which may facilitate the process parameters selections and achieve consistent build part quality through controlling the cooling rate.

An Experimental and Numerical Study of Dieless Water Jet Incremental Microforming

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Yi Shi ◽  
Weizhao Zhang ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Numerical Model ◽  
Sheet Metal ◽  
Process Parameters ◽  
High Speed ◽  
Tool Path ◽  
Numerical Study ◽  
Single Point ◽  
Thin Sheet ◽  
Water Jet ◽  
Truncated Cone

Conventional single-point incremental forming (SPIF) is already in use for small batch prototyping and fabrication of customized parts from thin sheet metal blanks by inducing plastic deformation with a rigid round-tip tool. The major advantages of the SPIF process are its high flexibility and die-free nature. In lieu of employing a rigid tool to incrementally form the sheet metal, a high-speed water jet as an alternative was proposed as the forming tool. Since there is no tool-workpiece contact in this process, unlike in the traditional SPIF process, no lubricant and rotational motion of the tool are required to reduce friction. However, the geometry of the part formed by water jet incremental microforming (WJIMF) will no longer be controlled by the motion of the rigid tool. On the contrary, process parameters such as water jet pressure, stage motion speed, water jet diameter, blank thickness, and tool path design will determine the final shape of the workpiece. This paper experimentally studies the influence of the above-mentioned key process parameters on the geometry of a truncated cone shape and on the corresponding surface quality. A numerical model is proposed to predict the shape of the truncated cone part after WJIMF with given input process parameters. The results prove that the formed part's geometric properties predicted by the numerical model are in excellent agreement with the actually measured ones. Arrays of miniature dots, channels, two-level truncated cones, and letters were also successfully fabricated on stainless-steel foils to demonstrate WJIMF capabilities.

scholarly journals Heat source management in wire-arc additive manufacturing process for Al-Mg and Al-Si alloys

2019 ◽  
Vol 26 ◽  
pp. 180-192 ◽  
Author(s):  
Kohei Oyama ◽  
Spyros Diplas ◽  
Mohammed M'hamdi ◽  
Anette E. Gunnæs ◽  
Amin S. Azar
Keyword(s):  
Additive Manufacturing ◽  
Heat Source ◽  
Manufacturing Process ◽  
Wire Arc Additive Manufacturing ◽  
Source Management

scholarly journals Fluctuation effects in Wire Arc Additive Manufacturing of aluminium analysed by high-speed imaging

2020 ◽  
Vol 56 ◽  
pp. 1088-1098
Author(s):  
Tobias Hauser ◽  
Adrien Da Silva ◽  
Raven T. Reisch ◽  
Joerg Volpp ◽  
Tobias Kamps ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
High Speed ◽  
High Speed Imaging ◽  
Fluctuation Effects ◽  
Wire Arc Additive Manufacturing
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