A study on the effect of substrate heating and cooling on bead geometry in wire arc additive manufacturing and its correlation with cooling rate

2020 ◽  
Author(s):  
Srinath Gudur ◽  
Vishwanath Nagallapati ◽  
Sagar Pawar ◽  
Gopinath Muvvala ◽  
Suryakumar Simhambhatla
Keyword(s):  
Additive Manufacturing ◽  
Cooling Rate ◽  
Bead Geometry ◽  
Substrate Heating ◽  
Heating And Cooling ◽  
Wire Arc Additive Manufacturing

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.

Wire arc additive manufacturing of Invar parts: bead geometry and melt pool monitoring

Measurement ◽  
2021 ◽  
pp. 110452
Author(s):  
Fernando Veiga ◽  
Alfredo Suarez ◽  
Eider Aldalur ◽  
Teresa Artaza
Keyword(s):  
Additive Manufacturing ◽  
Bead Geometry ◽  
Melt Pool ◽  
Wire Arc Additive Manufacturing

Using Unsupervised Learning for Regulating Deposition Speed During Robotic Wire Arc Additive Manufacturing

2021 ◽  
Author(s):  
Ashish Kulkarni ◽  
Prahar M. Bhatt ◽  
Alec Kanyuck ◽  
Satyandra K. Gupta
Keyword(s):  
Additive Manufacturing ◽  
Unsupervised Learning ◽  
Molten Metal ◽  
Length Variation ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Arc Length ◽  
Regulation Scheme ◽  
Speed Regulation ◽  
Wire Arc Additive Manufacturing

Abstract Robotic Wire Arc Additive Manufacturing (WAAM) is the layer-by-layer deposition of molten metal to build a three-dimensional part. In this process, the fed metal wire is melted using an electric arc as a heat source. The process is sensitive to the arc conditions, such as arc length. While building WAAM parts, the metal beads overlap at corners causing material accumulation. Material accumulation is undesirable as it leads to uneven build height and process failures caused by arc length variation. This paper introduces a deposition speed regulation scheme to avoid the corner accumulation problem and build parts with uniform build height. The regulated speed has a complex relationship with the corner angle, bead geometry, and molten metal dynamics. So we need to train a model that can predict suitable speed regulations for corner angles encountered while building the part. We develop an unsupervised learning technique to characterize the uniformity of the bead profile of a WAAM built layer and check for anomalous bead profiles. We train a model using these results that can predict suitable speed regulation parameters for different corner angles. We test this model by building a WAAM part using our speed regulation scheme and validate if the built part has uniform build height and reduced corner defects.

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.

Mapping of Bead Geometry in Wire Arc Additive Manufacturing Systems Using Passive Vision

2022 ◽  
Author(s):  
Marcus O. Couto ◽  
Arthur G. Rodrigues ◽  
Fernando Coutinho ◽  
Ramon R. Costa ◽  
Antonio C. Leite ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Bead Geometry ◽  
Wire Arc Additive Manufacturing

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

Processes ◽  
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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