Thermal simulation of wire arc additive manufacturing: a new material deposition and heat input modelling

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

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Metal transfer modes for Wire Arc Additive Manufacturing Al-Mg alloys: Influence of heat input in microstructure and porosity

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2021.117271 ◽

2021 ◽

pp. 117271

Author(s):

E. Aldalur ◽

A. Suárez ◽

F. Veiga

Keyword(s):

Additive Manufacturing ◽

Heat Input ◽

Metal Transfer ◽

Mg Alloys ◽

Wire Arc Additive Manufacturing ◽

Al Mg Alloys

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Effects of Material Properties on Angular Distortion in Wire Arc Additive Manufacturing: Experimental and Computational Analyses

Materials ◽

10.3390/ma13061399 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1399

Author(s):

Sang-Cheol Park ◽

Hee-Seon Bang ◽

Woo-Jae Seong

Keyword(s):

Additive Manufacturing ◽

Material Properties ◽

Heat Input ◽

Coefficient Of Thermal Expansion ◽

Angular Distortion ◽

Substrate Thickness ◽

Deformation Characteristics ◽

Temperature Dependent ◽

Temperature Dependent Properties ◽

Wire Arc Additive Manufacturing

In wire arc additive manufacturing (AM), as in arc welding, arc heat thermally deforms substrates and articles. For industrial applications, deformation characteristics of various materials must be understood and appropriate materials and methods of reducing deformation must be devised. Therefore, angular distortions of different materials were investigated through bead-on-plate welding and finite element analysis. A model that simplifies temperature-dependent properties was developed to establish relationships between thermomechanical properties and angular distortion. A simplified model of temperature-dependent properties was used, and angular distortion characteristics were extensively investigated for different material properties and heat inputs. Coefficient of thermal expansion, density, and specific heat all notably affected angular distortion depending on heat input conditions. Results showed that during wire arc AM, flatness of both substrates and articles could vary depending on material properties, heat input, substrate thickness, and bead accumulation. Study findings can provide insight into deformation characteristics of new materials and how to mitigate thermal distortions.

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Regional Control and Optimization of Heat Input during CMT by Wire Arc Additive Manufacturing: Modeling and Microstructure Effects

Materials ◽

10.3390/ma14051061 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1061

Author(s):

Furong Chen ◽

Yihang Yang ◽

Hualong Feng

Keyword(s):

Additive Manufacturing ◽

Deposition Rate ◽

Thermal History ◽

Heat Input ◽

Great Influence ◽

Input Process ◽

Cooling Process ◽

Average Grain Size ◽

Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) of aluminum-magnesium (Al–Mg) ER5356 alloy deposits is accomplished by cold metal transfer (CMT). During the process, the temperature change of the alloy deposits has a great influence on molding quality, and the microstructure and properties of alloy deposits are also affected by the complex thermal history of the additive manufacturing process. Here, we used an inter-layer cooling process and controlled the heat input process to attempt to reduce the influence of thermal history on alloy deposits during the additive process. The results showed that inter-layer cooling can optimize the molding quality of alloy deposits, but with the disadvantages of a long test time and slow deposition rate. A simple and uniform reduction of heat input makes the molding quality worse, but controlling the heat input by regions can optimize the molding quality of the alloy deposits. The thermophysical properties of Al-Mg alloy deposits were measured, and we found that the specific heat capacity and thermal diffusivity of alloy deposits were not obviously affected by the temperature. The microstructure and morphology of the deposited specimens were observed and analyzed by microscope and electron back-scatter diffraction (EBSD). The process of controlled heat input results in a higher deposition rate, less side-wall roughness, minimum average grain size, and less coarse recrystallization. In addition, different thermal histories lead to different texture types in the inter-layer cooling process. Finally, a controlled heat input process yields the highest average microhardness of the deposited specimen, and the fluctuation range is small. We expect that the process of controlling heat input by model height region will be widely used in the WAAM field.

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Wire arc additive manufacturing of thin-wall low-carbon steel parts: Microstructure and mechanical properties

International Journal of Modern Physics B ◽

10.1142/s0217979220401542 ◽

2020 ◽

Vol 34 (22n24) ◽

pp. 2040154

Author(s):

Van Thao Le ◽

Tien Long Banh ◽

Duc Toan Nguyen ◽

Van Tao Le

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Carbon Steel ◽

Heat Input ◽

Low Carbon Steel ◽

Production Costs ◽

High Deposition Rate ◽

Thin Wall ◽

Low Carbon ◽

Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) has received much attention for manufacturing metal parts with medium and large dimensions because of its high deposition rate and low production costs. In this study, the effects of the heat input on the microstructure formation of thin-wall low-carbon steel parts built by a WAAM process were addressed. The mechanical properties of built materials were also studied. The results indicate that the heat input significantly influences on the shape of built thin walls, but has slight effects on the microstructure evolution of built materials. The WAAM thin-wall low-carbon steel presents suitable microstructures and good tensile strengths (YS: 320 – 362 MPa, UTS: 429 – 479 MPa) that are adequate with industrial applications.

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On the Effect of Heat Input and Interpass Temperature on the Performance of Inconel 625 Alloy Deposited Using Wire Arc Additive Manufacturing–Cold Metal Transfer Process

Metals ◽

10.3390/met12010046 ◽

2021 ◽

Vol 12 (1) ◽

pp. 46

Author(s):

Chengxun Zhang ◽

Zhijun Qiu ◽

Hanliang Zhu ◽

Zhiyang Wang ◽

Ondrej Muránsky ◽

...

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Heat Input ◽

Inconel 625 ◽

Heat Accumulation ◽

Cold Metal Transfer ◽

Inconel 625 Alloy ◽

Cold Metal ◽

Wire Arc Additive Manufacturing ◽

Interpass Temperature

Relatively high heat input and heat accumulation are treated as critical challenges to affect the qualities and performances of components fabricated by wire arc additive manufacturing (WAAM). In this study, various heat inputs, namely 276, 552 and 828 J/mm, were performed to fabricate three thin-wall Inconel 625 structures by cold metal transfer (CMT)-based WAAM, respectively, and active interpass cooling was conducted to limit heat accumulation. The macrostructure, microstructure and mechanical properties of the produced components by CMT were investigated. It was found that the increased heat input can deteriorate surface roughness, and the size of dendrite arm spacing increases with increasing heat input, thus leading to the deterioration of mechanical properties. Lower heat input and application of active interpass cooling can be an effective method to refine microstructure and reduce anisotropy. This study enhances the understanding of interpass temperature control and the effectiveness of heat inputs for Inconel 625 alloy by WAAM. It also provides a valuable in situ process for microstructure and mechanical properties’ refinement of WAAM-fabricated alloys and the control of heat accumulation for the fabrication of large-sized structures for future practical applications.

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Evaluation of Bead Geometry for Aluminum Parts Fabricated Using Additive Manufacturing-Based Wire-Arc Welding

Processes ◽

10.3390/pr8101211 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1211

Author(s):

Hee-keun Lee ◽

Jisun Kim ◽

Changmin Pyo ◽

Jaewoong Kim

Keyword(s):

Additive Manufacturing ◽

Heat Input ◽

Deposition Efficiency ◽

Bead Geometry ◽

Thin Wall ◽

Cross Sectional ◽

Voltage Ratio ◽

Input Range ◽

The Cross ◽

Wire Arc Additive Manufacturing

The wire arc additive manufacturing (WAAM) process used to manufacture aluminum parts has a number of variables. This study focuses on the effects of the heat input and the current and voltage ratio on the deposition efficiency. The effects of the heat input and current and voltage ratio (V/A) on the bead geometry were analyzed, depending on the cross-sectional geometry of the deposition layers, for nine different deposition conditions. The deposition efficiency was also analyzed by analyzing the cross-sectional geometry of the thin-wall parts made of aluminum. The heat input range was about 2.7 kJ/cm to 4.5 kJ/cm; the higher the heat input, the higher the deposition efficiency. The maximum deposition efficiency achieved in this study was 76%. The current and voltage ratio was used to quantify the portion of voltage (V) in the total heat input (Q), and the effect on the bead geometry was analyzed. As the portion of voltage in the quasi heat input decreased by about 10%, it was found that the deposition efficiency was decreased by 1% to 3%.

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