Non-destructive testing application of radiography and ultrasound for wire and arc additive manufacturing

Lopez, Ana Beatriz; Bacelar, Ricardo; Pires, Inês; Santos, Telmo G.; Sousa, José Pedro; Quintino, L.

doi:10.1016/j.addma.2018.03.020

Cited by 133 publications

(110 citation statements)

References 8 publications

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“…This inspection is usually performed offline, that is, after welding. However, when it comes to additive manufacturing, online inspection is mostly wanted, since a layerby-layer monitoring is most appropriate to detect defects earlier in production of the parts, allowing its correction and the adjustment of the process parameters [117]. Also, due to the complex shape of the parts, inspection of the finished product can be very difficult to perform, and this is critical for structural parts.…”

Section: Microstructural Effects In Fusion-based Additive Manufacturingmentioning

confidence: 99%

Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Oliveira

Santos

Miranda

2020

Progress in Materials Science

449

134

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Additive manufacturing technologies based on melting and solidification have considerable similarities with fusion-based welding technologies, either by electric arc or high-power beams. However, several concepts are being introduced in additive manufacturing which have been extensively used in multipass arc welding with filler material. Therefore, clarification of fundamental definitions is important to establish a common background between welding and additive manufacturing research communities. This paper aims to review these concepts, highlighting the distinctive characteristics of fusion welding that can be embraced by additive manufacturing, namely the nature of rapid thermal cycles associated to small size and localized heat sources, the non-equilibrium nature of rapid solidification and its effects on: internal defects formation, phase transformations, residual stresses and distortions. Concerning process optimization, distinct criteria are proposed based on geometric, energetic and thermal considerations, allowing to determine an upper bound limit for the optimum hatch distance during additive manufacturing. Finally, a unified equation to compute the energy density is proposed. This equation enables to compare works performed with distinct equipment and experimental conditions, covering the major process parameters: power, travel speed, heat source dimension, hatch distance, deposited layer thickness and material grain size.

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Section: Microstructural Effects In Fusion-based Additive Manufacturingmentioning

confidence: 99%

Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Oliveira

Santos

Miranda

2020

Progress in Materials Science

449

134

View full text Add to dashboard Cite

show abstract

“…e disadvantage of WAAM technology is that its manufacturing accuracy is not as good as that of laser additive manufacturing and electron beam additive manufacturing [16][17][18][19][20]. In recent years, WAAM technology has attracted considerable attention in the aerospace industry, mechanical equipment industry, and other fields [21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Properties of a 2.25Cr1Mo0.25V Heat‐Resistant Steel Produced by Wire Arc Additive Manufacturing

Guo

Liu

et al. 2020

Advances in Materials Science and Engineering

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Wire arc additive manufacturing (WAAM) technology was used to produce samples of a 2.25Cr1Mo0.25V heat-resistant steel. The phase composition, microstructure, and crystal structure of the investigated material in the as-cladded state and postcladding heat-treated (705°C × 1 h) state were analysed by optical emission spectrometry (OES), optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The properties of the investigated material in the as-cladded state and postcladding heat-treated (705°C × 1 h) state were determined by a microhardness tester, mechanical properties tester, and Charpy impact tester. Through a study of the microstructure and properties, it is found that the investigated material produced by WAAM exhibits good forming quality and excellent metallurgical bonding properties, and no obvious defects are found. The microstructure consists mainly of Bg (granular bainite) and troostite precipitated at the grain boundaries. The results from high-resolution transmission electron microscopy observations show that the crystal structures of the 2.25Cr1Mo0.25V heat-resistant steel samples produced by WAAM in the as-cladded condition have many defects, such as dislocations and martensite-austenite (M-A) constituents, and their grain edges are sharp. There is a dramatic decrease in the dislocations in the 2.25Cr1Mo0.25V heat-resistant steel samples produced by the WAAM condition after the postcladding heat treatment (705°C × 1 h), and the grains become smooth. The distribution of the microhardness in the longitudinal and transverse cross sections of the samples is very uniform. The average longitudinal and transverse microhardness of the samples in the as-cladded state is 310 HV0.5 and 324 HV0.5, respectively. The average longitudinal and transverse microhardness of the samples after post-cladding heat treatment is 227 HV0.5 and 229 HV0.5, respectively. The yield strength of the samples without a postcladding heat treatment is 743 MPa, the tensile strength is 951 MPa, the elongation is 10%, and the Charpy impact value at -20°C is 15 J. After the postcladding heat treatment, the yield strength, tensile strength, elongation, and Charpy impact value of the samples are 611 MPa, 704 MPa, 14.5%, and 70 J, respectively.

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“…Non-destructive techniques are currently the experimental procedures that allow the inspection and the identification of the flaws during and after the deposition process. Among these techniques, the capabilities of ultrasonic testing have recently been investigated by researchers to develop reliable procedures for the process monitoring and the quality control of AM components [15,16]. In particular, in Sol, T. et al [15] the pulse-echo ultrasonic method was performed in order to investigate the mechanical behavior of selective laser melting additively manufactured AlSi 10 Mg. A slight elastic anisotropy with symmetry along the build direction was identified by means of ultrasonic tests.…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic Characterization of Components Manufactured by Direct Laser Metal Deposition

et al. 2020

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Direct laser metal deposition (DLMD) is an innovative additive technology becoming of key importance in the field of repairing applications for industrial and aeronautical components. The performance of the repaired components is highly related to the intrinsic presence of defects, such as cracks, porosity, excess of dilution or debonding between clad and substrate. Usually, the quality of depositions is evaluated through destructive tests and microstructural analysis. Clearly, such methodologies are inapplicable in-process or on repaired components. The proposed work aims to evaluate the capability of ultrasonic techniques to perform the mechanical characterization of additive manufactured (AM) components. The tested specimens were manufactured by DLMD using a nickel-based superalloy deposited on an AISI 304 substrate. Ultrasonic goniometric immersion tests were performed in order to mechanical characterize the substrate and the new material obtained by AM process, consisting of the substrate and the deposition. Furthermore, the relationship was evaluated between the acoustic and the mechanical properties of the AM components and the deposition process parameters and the geometrical characteristics of multiclad depositions, respectively. Finally, the effectiveness of the proposed non-destructive experimental approach for the characterization of the created deposition anomalies has been investigated.

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Non-destructive testing application of radiography and ultrasound for wire and arc additive manufacturing

Cited by 133 publications

References 8 publications

Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Microstructure and Properties of a 2.25Cr1Mo0.25V Heat‐Resistant Steel Produced by Wire Arc Additive Manufacturing

Ultrasonic Characterization of Components Manufactured by Direct Laser Metal Deposition

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