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

Materials ◽  
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.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

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.

scholarly journals Analysis of the Machining Process of Titanium Ti6Al-4V Parts Manufactured by Wire Arc Additive Manufacturing (WAAM)

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 766 ◽  
Author(s):  
Fernando Veiga ◽  
Alain Gil Del Val ◽  
Alfredo Suárez ◽  
Unai Alonso
Keyword(s):  
Additive Manufacturing ◽  
Arc Welding ◽  
Machine Tools ◽  
Optimal Strategies ◽  
Machining Process ◽  
Manufacturing Processes ◽  
Plasma Arc Welding ◽  
Traditional Manufacturing ◽  
Wire Arc Additive Manufacturing

In the current days, the new range of machine tools allows the production of titanium alloy parts for the aeronautical sector through additive technologies. The quality of the materials produced is being studied extensively by the research community. This new manufacturing paradigm also opens important challenges such as the definition and analysis of the optimal strategies for finishing-oriented machining in this type of part. Researchers in both materials and manufacturing processes are making numerous advances in this field. This article discusses the analysis of the production and subsequent machining in the quality of TI6Al4V produced by Wire Arc Additive Manufacturing (WAAM), more specifically Plasma Arc Welding (PAW). The promising results observed make it a viable alternative to traditional manufacturing methods.

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

Materials ◽  
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.

scholarly journals Stable honeycomb structures and temperature based trajectory optimization for wire-arc additive manufacturing

2020 ◽  
Author(s):  
Martin Bähr ◽  
Johannes Buhl ◽  
Georg Radow ◽  
Johannes Schmidt ◽  
Markus Bambach ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Trajectory Optimization ◽  
Tool Path ◽  
Honeycomb Structure ◽  
Mixed Integer ◽  
Voronoi Tesselation ◽  
Integer Linear Programming Problem ◽  
Mathematical Problems ◽  
Wire Arc Additive Manufacturing

Abstract We consider two mathematical problems that are connected and occur in the layer-wise production process of a workpiece using wire-arc additive manufacturing. As the first task, we consider the automatic construction of a honeycomb structure, given the boundary of a shape of interest. In doing this, we employ Lloyd’s algorithm in two different realizations. For computing the incorporated Voronoi tesselation we consider the use of a Delaunay triangulation or alternatively, the eikonal equation. We compare and modify these approaches with the aim of combining their respective advantages. Then in the second task, to find an optimal tool path guaranteeing minimal production time and high quality of the workpiece, a mixed-integer linear programming problem is derived. The model takes thermal conduction and radiation during the process into account and aims to minimize temperature gradients inside the material. Its solvability for standard mixed-integer solvers is demonstrated on several test-instances. The results are compared with manufactured workpieces.

scholarly journals Towards Intelligent Monitoring System in Wire Arc Additive Manufacturing: A Surface Anomaly Detector on a Small Dataset

2021 ◽  
Author(s):  
Yuxing Li ◽  
Haocheng Mu ◽  
Joseph Polden ◽  
Huijun Li ◽  
Lei Wang ◽  
...  
Keyword(s):  
Image Processing ◽  
Additive Manufacturing ◽  
Monitoring System ◽  
Processing System ◽  
Image Processing System ◽  
Layer Deposition ◽  
Anomaly Detector ◽  
Precision Assessment ◽  
Wire Arc Additive Manufacturing

Abstract Rapid developments in artificial intelligence and image processing have presented many new opportunities for defect detection in manufacturing processes. In this work, an intelligent image processing system has been developed to monitor inter-layer deposition quality during a Wire Arc Additive Manufacturing (WAAM) process. Information produced from this system is to be used in conjunction with other quality monitoring systems to verify the quality of fabricated components. It is tailored to identify the presence of defects relating to lack-of-fusion and voids immediately after the deposition of a given layer. The image processing system is built upon the YOLOv3 architecture and through moderate changes on anchor settings, achieves 53% precision on surface anomaly detection and 100% accuracy in identifying the fabricated components’ location, providing a prerequisite for high precision assessment of welding quality. The work presented in this paper presents an inter-layer vision-based defect monitoring system in WAAM and serves to highlight the feasibility of developing such intelligent computer vision systems for monitoring the WAAM process for defects.

scholarly journals Hot-wire arc additive manufacturing of aluminum alloy with reduced porosity and high deposition rate

2021 ◽  
Vol 199 ◽  
pp. 109370
Author(s):  
Rui Fu ◽  
Shuiyuan Tang ◽  
Jiping Lu ◽  
Yinan Cui ◽  
Zixiang Li ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Additive Manufacturing ◽  
Deposition Rate ◽  
High Deposition Rate ◽  
Hot Wire ◽  
Wire Arc Additive Manufacturing

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

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.

scholarly journals The Influence of Heat Input on the Surface Quality of Wire and Arc Additive Manufacturing

2021 ◽  
Vol 11 (21) ◽  
pp. 10201
Author(s):  
Jiayi Zeng ◽  
Wenzhong Nie ◽  
Xiaoxuan Li
Keyword(s):  
Additive Manufacturing ◽  
Standard Deviation ◽  
Root Mean Square ◽  
Surface Quality ◽  
Heat Input ◽  
Quantitative Description ◽  
Mean Square ◽  
Profile Model ◽  
The Ideal

Wire and arc additive manufacturing has unique process characteristics, which make it have great potential in many fields, but the large amount of heat input brought by this feature limits its practical application. The influence of heat input on the performance of parts has been extensively studied, but the quantitative description of the influence of heat input on the surface quality of parts by wire and arc additive manufacturing has not received enough attention. According to different heat input, select the appropriate process parameters for wire and arc additive manufacturing, reversely shape the profile model, select the appropriate function model to establish the ideal profile model according to the principle of minimum error, and compare the two models to analyze the effect of heat input on the surface quality of the parts manufactured by wire and arc additive manufacturing. The results show that, when the heat input is high or low, the standard deviation value and the root mean square value reach 1.908 and 1.963, respectively. The actual profile is larger than the ideal profile. When the heat input is moderate, the standard deviation value and the root mean square value are only 1.634 and 1.713, respectively, and the actual contour is in good agreement with the ideal contour. Combined with the analysis of the transverse and longitudinal sections, it is shown that the heat input has a high degree of influence on the surface quality of the specimen manufactured by wire and arc additive manufacturing, and higher or lower heat input is disadvantageous to it.

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