Wire arc additive manufacturing of hot work tool steel with CMT process

The successful and efficient production of parts with specific features by Wire + Arc Additive Manufacturing (WAAM) strongly depends on the selection of proper and typically interrelated deposition parameters. This task might be particularly challenging in the making of thin walls, which might be highly impacted by processing conditions and heat accumulation. In this context, this study aims at expanding the work envelope and optimizing the parametric conditions in WAAM with relative density and surface aspects of the preforms as quality constraints. The experimental approach was based on the deposition of thin Al5Mg walls by the CMT process on its standard welding setup and with an active cooling technique to enhance the deposition robustness. Internal voids were estimated by Archimedes’ method. The surface quality of the walls was assessed through the visual aspect and the surface waviness by cross-section analysis. All the conditions presented relative density higher than 98%. The upgrade of the standard welding hardware to WAAM purposes through the addition of a supplementary shielding gas nozzle to the torch and the intensity of the heat sinking from the part significantly expanded the process work envelope, with its applicability being successfully demonstrated with multi-objective optimization. To sum up, a decision-making procedure is presented towards achieving intended preform quality.

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“…• T: target wall width; • f(TWW): total wall width function-Equation ( 7); • f(EWW): effective wall width function-Equation (8).…”

Section: Numerical Optimization and Experimental Validationmentioning

confidence: 99%

Work Envelope Expansion and Parametric Optimization in WAAM with Relative Density and Surface Aspect as Quality Constraints: The Case of Al5Mg Thin Walls with Active Cooling

Silva

Teixeira

Araújo

et al. 2021

JMMP

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“…The analysis and reduction of heat input during WAAM is a key factor for the application of this technology. Therefore, investigations on energy reduced welding regimes were carried out [19,20]. Moreover, cooling strategies were developed to reduce interlayer temperatures and enhance processing times [21,22].…”

Section: Introduction and State Of The Artmentioning

confidence: 99%

Reduction of Energy Input in Wire Arc Additive Manufacturing (WAAM) with Gas Metal Arc Welding (GMAW)

et al. 2020

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Wire arc additive manufacturing (WAAM) by gas metal arc welding (GMAW) is a suitable option for the production of large volume metal parts. The main challenge is the high and periodic heat input of the arc on the generated layers, which directly affects geometrical features of the layers such as height and width as well as metallurgical properties such as grain size, solidification or material hardness. Therefore, processing with reduced energy input is necessary. This can be implemented with short arc welding regimes and respectively energy reduced welding processes. A highly efficient strategy for further energy reduction is the adjustment of contact tube to work piece distance (CTWD) during the welding process. Based on the current controlled GMAW process an increase of CTWD leads to a reduction of the welding current due to increased resistivity in the extended electrode and constant voltage of the power source. This study shows the results of systematically adjusted CTWD during WAAM of low-alloyed steel. Thereby, an energy reduction of up to 40% could be implemented leading to an adaptation of geometrical and microstructural features of additively manufactured work pieces.

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“…As a consequence, the phase composition at the middle is almost made up of tempered bainite, as shown in Figure 8c. When deposition arrives at the end, the melt pool emerges at a rapid cooling rate due to mass heat dissipation with the environment, which allows the tempered sorbite transformation to occur again [25]. At the same time, some ferrite transformation takes place due to the lack of subsequent heating.…”

Section: Phase Transformationmentioning

confidence: 99%

“…This phenomenon eventually results in different phase transformation in diverse regions. environment, which allows the tempered sorbite transformation to occur again [25]. At the same time, some ferrite transformation takes place due to the lack of subsequent heating.…”

Section: Phase Transformationmentioning

confidence: 99%

Microstructure and Mechanical Properties of Low-Carbon High-Strength Steel Fabricated by Wire and Arc Additive Manufacturing

Li-hua

Jiang

Huang

et al. 2020

Metals

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Wire and arc additive manufacturing (WAAM) is a novel technique for fabricating large and complex components applied in the manufacturing industry. In this study, a low-carbon high-strength steel component deposited by WAAM for use in ship building was obtained. Its microstructure and mechanical properties as well as fracture mechanisms were investigated. The results showed that the microstructure consisted of an equiaxed zone, columnar zone, and inter-layer zone, while the phases formed in different parts of the deposited component were different due to various thermal cycles and cooling rates. The microhardness of the bottom and top varied from 290 HV to 260 HV, caused by temperature gradients and an inhomogeneous microstructure. Additionally, the tensile properties in transversal and longitudinal orientations show anisotropy characteristics, which was further investigated using a digital image correlation (DIC) method. This experimental fact indicated that the longitudinal tensile property has an inferior performance and tends to cause stress concentrations in the inter-layer areas due to the inclusion of more inter-layer zones. Furthermore, electron backscattered diffraction (EBSD) was applied to analyze the difference in Taylor factor between the inter-layer area and deposited area. The standard deviation of the Taylor factor in the inter-layer area was determined to be 0.907, which was larger than that in the deposited area (0.865), indicating nonuniform deformation and local stress concentration occurred in inter-layer area. Finally, as observed from the fracture morphology on the fractured surface of the sample, anisotropy was also approved by the comparison of the transversal and longitudinal tensile specimens.

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Wire arc additive manufacturing of hot work tool steel with CMT process

Cited by 124 publications

References 30 publications

Work Envelope Expansion and Parametric Optimization in WAAM with Relative Density and Surface Aspect as Quality Constraints: The Case of Al5Mg Thin Walls with Active Cooling

Work Envelope Expansion and Parametric Optimization in WAAM with Relative Density and Surface Aspect as Quality Constraints: The Case of Al5Mg Thin Walls with Active Cooling

Reduction of Energy Input in Wire Arc Additive Manufacturing (WAAM) with Gas Metal Arc Welding (GMAW)

Microstructure and Mechanical Properties of Low-Carbon High-Strength Steel Fabricated by Wire and Arc Additive Manufacturing

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