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Article
Publication date: 2 August 2011

David Schick, Sudarsanam Suresh Babu, Daniel R. Foster, Marcelo Dapino, Matt Short and John C. Lippold

Ultrasonic additive manufacturing (UAM) is a rapid prototyping process through which multiple thin layers of material are sequentially ultrasonically welded together to…

Abstract

Purpose

Ultrasonic additive manufacturing (UAM) is a rapid prototyping process through which multiple thin layers of material are sequentially ultrasonically welded together to form a finished part. While previous research into the peak temperatures experienced during UAM have been documented, a thorough examination of the heating and cooling curves has not been conducted to date.

Design/methodology/approach

For this study, UAM weldments made from aluminum 3003‐H18 tapes with embedded Type‐K thermocouples were examined. Finite element modeling was used to compare the theoretical thermal diffusion rates during heating to the observed heating patterns. A model was used to calculate the effective thermal diffusivity of the UAM build on cooling based on the observed cooling curves and curve fitting analysis.

Findings

Embedded thermocouple data revealed simultaneous temperature increases throughout all interfaces of the UAM build directly beneath the sonotrode. Modeling of the heating curves revealed a delay of at least 0.5 seconds should have existed if heating of lower interfaces was a result of thermal diffusion alone. As this is not the case, it was concluded that ultrasonic energy is absorbed and converted to heat at every interface beneath the sonotrode. The calculated thermal diffusivity of the build on cooling was less than 1 percent of the reported values of bulk aluminum, suggesting that voids and oxides along interfaces throughout the build may be inhibiting thermal diffusion through thermal contact resistance across the interface.

Originality/value

This work systematically analyzed the thermal profiles that develop during the UAM process. The simultaneous heating phenomenon presented here has not been documented by other research programs. The findings presented here will enable future researchers to develop more accurate models of the UAM process, potentially leading to improved UAM bond quality.

Details

Rapid Prototyping Journal, vol. 17 no. 5
Type: Research Article
ISSN: 1355-2546

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Book part
Publication date: 24 July 2020

Lillian T. Eby, Melissa M. Robertson and David B. Facteau

Interest in employee mindfulness has increased dramatically in recent years, fueled by several important conceptual articles, numerous studies documenting the benefits of…

Abstract

Interest in employee mindfulness has increased dramatically in recent years, fueled by several important conceptual articles, numerous studies documenting the benefits of mindfulness for employee outcomes, and the adoption of mindfulness-based practices in many Fortune 500 organizations. Despite this growing interest, the vast majority of research on employee mindfulness has taken an intrapersonal focus, failing to appreciate the ways in which mindfulness may enhance work-related relational processes and outcomes. The authors explore possible associations between mindfulness and relationally oriented workplace phenomena, drawing from interdisciplinary scholarship examining mindfulness in romantic relationships, child–parent relationships, patient–healthcare provider relationships, and student–teacher relationships. A framework is proposed that links mindfulness to three distinct relationally oriented processes, which are expected to have downstream effects on work-related relational outcomes. The authors then take the proposed framework and discuss possible extensions to a variety of unique workplace relationships and discuss critical next steps in advancing the relational science of mindfulness.

Details

Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-80043-076-1

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Book part
Publication date: 15 December 2015

Pierre A. Balthazard and Robert W. Thatcher

Through a review of historically famous cases and a chronicle of neurotechnology development, this chapter discusses brain structure and brain function as two distinct yet…

Abstract

Through a review of historically famous cases and a chronicle of neurotechnology development, this chapter discusses brain structure and brain function as two distinct yet interrelated paths to understand the relative contributions of anatomical and physiological mechanisms to the human brain–behavior relationship. From an organizational neuroscience perspective, the chapter describes over a dozen neuroimaging technologies that are classified under four groupings: morphologic, invasive metabolic, noninvasive metabolic, and electromagnetic. We then discuss neuroimaging variables that may be useful in social science investigations, and we underscore electroencephalography as a particularly useful modality for the study of individuals and groups in organizational settings. The chapter concludes by considering emerging science and novel brain technologies for the organizational researcher as we look to the future.

Details

Organizational Neuroscience
Type: Book
ISBN: 978-1-78560-430-0

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Article
Publication date: 8 January 2020

Md. Rumman Ul Ahsan, Ali Newaz Mohammad Tanvir, Taylor Ross, Ahmed Elsawy, Min-Suk Oh and Duck Bong Kim

Wire + arc additive manufacturing (WAAM) uses existing welding technology to make a part from metal deposited in an almost net shape. WAAM is flexible in that it can use…

Abstract

Purpose

Wire + arc additive manufacturing (WAAM) uses existing welding technology to make a part from metal deposited in an almost net shape. WAAM is flexible in that it can use multiple materials successively or simultaneously during the manufacturing of a single component.

Design/methodology/approach

In this work, a gas metal arc welding (GMAW) based wire + arc additive manufacturing (WAAM) system has been developed to use two material successively and fabricate bimetallic additively manufactured structure (BAMS) of low carbon steel and AISI 316L stainless steel (SS).

Findings

The interface shows two distinctive zones of LCS and SS deposits without any weld defects. The hardness profile shows a sudden increase of hardness at the interface, which is attributed to the migration of chromium from the SS. The tensile test results show that the bimetallic specimens failed at the LCS side, as LCS has lower strength of the materials used.

Originality/value

The microstructural features and mechanical properties are studied in-depth with special emphasis on the bimetallic interface.

Details

Rapid Prototyping Journal, vol. 26 no. 3
Type: Research Article
ISSN: 1355-2546

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Book part
Publication date: 10 September 2021

Ignas Kalpokas

Abstract

Details

Malleable, Digital, and Posthuman
Type: Book
ISBN: 978-1-80117-621-7

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Book part
Publication date: 26 March 2020

Dean Bowman

This chapter seeks to reassess the film GoldenEye (Campbell, 1995), and its highly successful (Impellizeri, 2010) videogame adaptation GoldenEye 007 (Rare, 1997), in light…

Abstract

This chapter seeks to reassess the film GoldenEye (Campbell, 1995), and its highly successful (Impellizeri, 2010) videogame adaptation GoldenEye 007 (Rare, 1997), in light of the concept of the Hegemony of Play (Fron, Fullerton, Morie, & Pearce, 2007), which seeks to critique the dominance of the hypermasculine ‘gamer’ identity in videogame culture (a persona GoldenEye anticipates in its problematic character Boris Grishenko).

Since the gamer is bound up in the very technological materiality of videogames as a medium and an industry (Dyer-Witheford & de Peuter, 2009), central to this discussion is the significant yet highly ambivalent role technology continues to play in the Bond films, both extending and threatening (Leach, 2015; Nitins, 2010) Bond’s natural male skill and intuition (McGowan, 2010). Indeed, GoldenEye is a particularly salient study since many suggest Brosnan to be the most technologically adept (or dependent) of the Bonds (Rositzka, 2015; Willis, 2003), and I will argue that the film and game together explore just what happens when Bond’s implacable force meets the immutable technological object, providing a fascinating lens through which to read the larger technocultural shifts embodied in the transition to the immaterial economies of cognitive capitalism (Hardt & Negri, 2001) and their potential to disrupt traditional, patriarchal gender configurations (Haraway, 1991; Hayles, 2005; Plant, 1998; Wajcman, 2004).

Core to this is a critical reading of the game’s popular multiplayer mode, where exploration of whether technology can be understood to potentially level the gender playing field (Jones, 2015) or whether the fact that such technology is always already encoded as masculine (Chess, 2017) ultimately undercuts this ambition.

Details

From Blofeld to Moneypenny: Gender in James Bond
Type: Book
ISBN: 978-1-83867-163-1

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Article
Publication date: 4 August 2021

Sachin Ambade, Chetan Tembhurkar, Awanikumar P. Patil, Prakash Pantawane and Ravi Pratap Singh

The purpose of this study is on AISI 409 M ferritic stainless steel (FSS) which is developing a preferred choice for railway carriages, storage tanks and reactors in…

Abstract

Purpose

The purpose of this study is on AISI 409 M ferritic stainless steel (FSS) which is developing a preferred choice for railway carriages, storage tanks and reactors in chemical plants. The intergranular corrosion behavior of welded SS 409 M has been studied in H2SO4 solution (0.5 M) with the addition of NH4SCN (0.01 M) with different heat input. As this study is very important in context of various chemical and petrochemical industries.

Design/methodology/approach

The microstructure, mechanical properties and intergranular corrosion properties of AISI 409 M FSS using shielded metal arc welding were investigated. Shielded metal arc welding with different welding current values are used to change the heat input in the joints resulted in the microstructural variations. The microstructure of the welded steel was carefully inspected along the width of the heat-affected zone (HAZ) and the transverse-section of the thin plate.

Findings

The width of heat affected zone (3.1,4.2 and 5.8 mm) increases on increasing the welding heat input. Due to change in grain size (grain coarsening) as HAZ increased. From the microstructure, it was observed that the large grain growth which is dendritic and the structure become finer to increase in welding heat input. For lower heat input, the maximum microhardness value (388HV) was observed compared with medium (351 HV) and higher heat input (344 HV), which is caused by a rapid cooling rate and the depleted area of chromium (Cr) and nickel (Ni). The increase in weld heat input decreases tensile strength, i.e. 465 MPa, 440 MPa and 418 MPa for low, medium and high heat input, respectively. This is because of grain coarsening and chromium carbide precipitation in sensitized zone and wider HAZ. The degree of sensitization increases (27.04%, 31.86% and 36.08%) to increase welding heat input because of chromium carbide deposition at the grain boundaries. The results revealed that the higher degree of sensitization and the difference in intergranular corrosion behavior under high heat input are related to the grain growth in the HAZ and the weld zone.

Originality/value

The study is based on intergranular corrosion behavior of welded SS 409 M in H2SO4 solution (0.5 M) with the addition of NH4SCN (0.01 M) with different heat input which is rarely found in literature.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 March 1994

Trevor Galbraith

During the first half of this year the Association has continued to expand its exhibition programme by increasing its presence at overseas shows. Two DTI sponsored joint…

Abstract

During the first half of this year the Association has continued to expand its exhibition programme by increasing its presence at overseas shows. Two DTI sponsored joint venture groups have been formed, one to Nepcon West, the other to Nepcon Beijing. Anaheim saw the biggest UK group for over 10 years, with CEMA taking three separate blocks in different sectors of the show. There is no doubt from the reception we received that CEMA is now firmly established at Nepcon West. We enjoyed tremendous support from both the British Consulate and the British‐American Chamber of Commerce with their President making several visits to the CEMA booth.

Details

Circuit World, vol. 20 no. 4
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 15 June 2015

Luke N. Carter, Khamis Essa and Moataz M Attallah

The purpose of this paper is to optimise the selective laser melting (SLM) process parameters for CMSX486 to produce a “void free” (fully consolidated) material, whilst…

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Abstract

Purpose

The purpose of this paper is to optimise the selective laser melting (SLM) process parameters for CMSX486 to produce a “void free” (fully consolidated) material, whilst reducing the cracking density to a minimum providing the best possible fabricated material for further post-processing. SLM of high temperature nickel base superalloys has had limited success due to the susceptibly of the material to solidification and reheat cracking.

Design/methodology/approach

Samples of CMSX486 were fabricated by SLM. Statistical design of experiments (DOE) using the response surface method was used to generate an experimental design and investigate the influence of the key process parameters (laser power, scan speed, scan spacing and island size). A stereological technique was used to quantify the internal defects within the material, providing two measured responses: cracking density and void per cent.

Findings

The analysis of variance (ANOVA) was used to determine the most significant process parameters and showed that laser power, scan speed and the interaction between the two are significant parameters when considering the cracking density. Laser power, scan speed, scan spacing and the interaction between power and speed, and speed and spacing were the significant factors when considering void per cent. The optimum setting of the process parameters that lead to minimum cracking density and void per cent was obtained. It was shown that the nominal energy density can be used to identify a threshold for the elimination of large voids; however, it does not correlate well to the formation of cracks within the material. To validate the statistical approach, samples were produced using the predicted optimum parameters in an attempt to validate the response surface model. The model showed good prediction of the void per cent; however, the cracking results showed a greater deviation from the predicted value.

Originality/value

This is the first ever study on SLM of CMSX486. The paper shows that provided that the process parameters are optimised, SLM has the potential to provide a low-cost route for the small batch production of high temperature aerospace components.

Details

Rapid Prototyping Journal, vol. 21 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 18 November 2019

Vinoth Kumar M. and Balasubramanian V.

Super 304HCu super austenitic stainless steel tubes containing 2.3 to 3 (Wt.%) of copper (Cu) is used in superheaters and reheater tubings of nuclear power plants. In…

Abstract

Purpose

Super 304HCu super austenitic stainless steel tubes containing 2.3 to 3 (Wt.%) of copper (Cu) is used in superheaters and reheater tubings of nuclear power plants. In general, austenitic stainless steels welded by conventional constant current gas tungsten arc welding (CC-GTAW) produce coarse columnar grains, alloy segregation and may result in inferior mechanical properties. Pulsed current gas tungsten arc welding (PC-GTAW) can control the solidification structure by altering the prevailing thermal gradients in the weld pool.

Design/methodology/approach

Super 304HCu tubes of Ø 57.1 mm and the wall thickness of 3.5 mm were autogenously welded using CC and PC-GTAW processes. Joints are characterized using optical microscopy, electron microscopy, energy dispersive spectroscopy and electron backscatter diffraction (EBSD) techniques. Hot tensile properties of the weld joints were evaluated and correlated with their microstructural features.

Findings

Current pulsing in GTAW has resulted in minimal eutectic film segregation, lower volume % of delta ferrite and appreciable improvement in tensile properties than CC-GTAW joints.

Originality/value

The EBSD boundary map and inverse pole orientation map of Super 304HCu weld joints evidence the grain refinement and much frequent high angle grain boundaries achieved using weld current pulsing.

Details

World Journal of Engineering, vol. 16 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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