Review on electron beam based additive manufacturing

2019 ◽  
Vol 26 (3) ◽  
pp. 485-498 ◽  
Author(s):  
Seema Negi ◽  
Athul Arun Nambolan ◽  
Sajan Kapil ◽  
Prathamesh Shreekant Joshi ◽  
Manivannan R. ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Research And Development ◽  
Design Methodology ◽  
Scanning Speed ◽  
Working Environment ◽  
Current Status ◽  
Layer By Layer ◽  
Content Type ◽  
High Scanning Speed

Purpose Electron beam-based additive manufacturing (EBAM) is an emerging technology to produce metal parts layer-by-layer. The purpose of this paper is to systematically address the research and development carried out for this technology, up till now. Design/methodology/approach This paper identifies several aspects of research and development in EBAM. Findings Electron beam has several unique advantages such as high scanning speed, energy efficiency, versatility for several materials and better part integrity because of a vacuum working environment. Originality/value This paper provides information on different aspects of EBAM with the current status and future scope.

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

scholarly journals Contactless temperature measurement in wire-based electron beam additive manufacturing Ti-6Al-4V

2021 ◽  
Author(s):  
F. Pixner ◽  
R. Buzolin ◽  
S. Schönfelder ◽  
D. Theuermann ◽  
F. Warchomicka ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Thermal Imaging ◽  
Temperature Profiles ◽  
Layer By Layer ◽  
Thermal Cycles ◽  
Cooling Rates ◽  
Geometric Boundary ◽  
Microstructural Characterisation ◽  
Local Misorientation

AbstractThe complex thermal cycles and temperature distributions observed in additive manufacturing (AM) are of particular interest as these define the microstructure and the associated properties of the part being built. Due to the intrinsic, layer-by-layer material stacking performed, contact methods to measure temperature are not suitable, and contactless methods need to be considered. Contactless infrared irradiation techniques were applied by carrying out thermal imaging and point measurement methods using pyrometers to determine the spatial and temporal temperature distribution in wire-based electron beam AM. Due to the vacuum, additional challenges such as element evaporation must be overcome and additional shielding measures were taken to avoid interference with the contactless techniques. The emissivities were calibrated by thermocouple readings and geometric boundary conditions. Thermal cycles and temperature profiles were recorded during deposition; the temperature gradients are described and the associated temperature transients are derived. In the temperature range of the α+β field, the cooling rates fall within the range of 180 to 350 °C/s, and the microstructural characterisation indicates an associated expected transformation of β→α'+α with corresponding cooling rates. Fine acicular α and α’ formed and local misorientation was observed within α as a result of the temperature gradient and the formation of the α’.

The role of robotics in additive manufacturing: review of the AM processes and introduction of an intelligent system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J. Norberto Pires ◽  
Amin S. Azar ◽  
Filipe Nogueira ◽  
Carlos Ye Zhu ◽  
Ricardo Branco ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Intelligent System ◽  
Material Selection ◽  
High Strength Steels ◽  
Industrial Applications ◽  
Layer By Layer ◽  
Content Type ◽  
Functional Components

Purpose Additive manufacturing (AM) is a rapidly evolving manufacturing process, which refers to a set of technologies that add materials layer-by-layer to create functional components. AM technologies have received an enormous attention from both academia and industry, and they are being successfully used in various applications, such as rapid prototyping, tooling, direct manufacturing and repair, among others. AM does not necessarily imply building parts, as it also refers to innovation in materials, system and part designs, novel combination of properties and interplay between systems and materials. The most exciting features of AM are related to the development of radically new systems and materials that can be used in advanced products with the aim of reducing costs, manufacturing difficulties, weight, waste and energy consumption. It is essential to develop an advanced production system that assists the user through the process, from the computer-aided design model to functional components. The challenges faced in the research and development and operational phase of producing those parts include requiring the capacity to simulate and observe the building process and, more importantly, being able to introduce the production changes in a real-time fashion. This paper aims to review the role of robotics in various AM technologies to underline its importance, followed by an introduction of a novel and intelligent system for directed energy deposition (DED) technology. Design/methodology/approach AM presents intrinsic advantages when compared to the conventional processes. Nevertheless, its industrial integration remains as a challenge due to equipment and process complexities. DED technologies are among the most sophisticated concepts that have the potential of transforming the current material processing practices. Findings The objective of this paper is identifying the fundamental features of an intelligent DED platform, capable of handling the science and operational aspects of the advanced AM applications. Consequently, we introduce and discuss a novel robotic AM system, designed for processing metals and alloys such as aluminium alloys, high-strength steels, stainless steels, titanium alloys, magnesium alloys, nickel-based superalloys and other metallic alloys for various applications. A few demonstrators are presented and briefly discussed, to present the usefulness of the introduced system and underlying concept. The main design objective of the presented intelligent robotic AM system is to implement a design-and-produce strategy. This means that the system should allow the user to focus on the knowledge-based tasks, e.g. the tasks of designing the part, material selection, simulating the deposition process and anticipating the metallurgical properties of the final part, as the rest would be handled automatically. Research limitations/implications This paper reviews a few AM technologies, where robotics is a central part of the process, such as vat photopolymerization, material jetting, binder jetting, material extrusion, powder bed fusion, DED and sheet lamination. This paper aims to influence the development of robot-based AM systems for industrial applications such as part production, automotive, medical, aerospace and defence sectors. Originality/value The presented intelligent system is an original development that is designed and built by the co-authors J. Norberto Pires, Amin S. Azar and Trayana Tankova.

Episodic supply chains at times of disruption

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Christina Öberg
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Supply Chains ◽  
Design Methodology ◽  
Secondary Data ◽  
Transformational Change ◽  
Content Type ◽  
Metal Additive Manufacturing ◽  
Contemporary Technology ◽  
Metal Additive

Purpose Additive manufacturing has been described as converting supply chains into demand chains. By focusing on metal additive manufacturing as a contemporary technology causing ongoing disruption to the supply chain, the purpose of this paper is to describe and discuss how incumbent firms act during an ongoing, transformational disruption of their supply chain. Design/methodology/approach Interviews and secondary data, along with seminars attracting approximately 600 individuals operating in metal additive manufacturing, form the empirical basis for this paper. Findings The findings of this paper indicate how disruption occurs at multiple positions in the supply chain. Episodic positions as conceptualised in this paper refer to how parties challenged by disruption attempt to reach normality while speeding the transformational disruption. Originality/value This paper contributes to previous research by theorising about episodic positions in light of a supply chain disruption. The empirical data are unique in how they capture supply chain change at the time of disruption and illustrate disruptive, transformational change to supply chains. The paper interlinks research on disruption from the innovation and supply chain literature, with contributions to both.

3D printing technology in musical instrument research: reviewing the potential

2018 ◽  
Vol 24 (9) ◽  
pp. 1511-1523 ◽  
Author(s):  
Antreas Kantaros ◽  
Olaf Diegel
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Musical Instrument ◽  
Musical Instruments ◽  
Wind Instruments ◽  
Content Type ◽  
New Class ◽  
History Of ◽  
New Applications ◽  
Practical Implications

Purpose This paper aims to discuss additive manufacturing (AM) in the context of applications for musical instruments. It examines the main AM technologies used in musical instruments, goes through a history of musical applications of AM and raises the questions about the application of AM to create completely new wind instruments that would be impossible to produce with conventional manufacturing. Design/methodology/approach A literature research is presented which covers a historical application of AM to musical instruments and hypothesizes on some potential new applications. Findings AM has found extensive application to create conventional musical instruments with unique aesthetics designs. It’s true potential to create entirely new sounds, however, remains largely untapped. Research limitations/implications More research is needed to truly assess the potential of additive manufacturing to create entirely new sounds for musical instrument. Practical implications The application of AM in music could herald an entirely new class of musical instruments with unique sounds. Originality/value This study highlights musical instruments as an unusual application of AM. It highlights the potential of AM to create entirely new sounds, which could create a whole new class of musical instruments.

A directed content analysis of viewpoints on the changing patterns of Lean Six Sigma research

2019 ◽  
Vol 31 (4) ◽  
pp. 641-654 ◽  
Author(s):  
Bryan A. Rodgers ◽  
Jiju Antony ◽  
Zhen He ◽  
Elizabeth A. Cudney ◽  
Chad Laux
Keyword(s):  
Continuous Improvement ◽  
Six Sigma ◽  
Design Methodology ◽  
Lean Six Sigma ◽  
Current Status ◽  
Short Term ◽  
Content Type ◽  
Changing Patterns ◽  
Practical Implications

Purpose The purpose of this paper, builds on previous studies that explored the research patterns over 15 years, is to consider the current status of the integration of Lean and Six Sigma. More specifically, this research addresses whether Lean and Six Sigma are stronger together and explores the reasons why Lean researchers and practitioners may be less likely to integrate Six Sigma in their work. Design/methodology/approach The research utilises a survey of 25 established and respected academics and practitioners from 16 countries. The questionnaire is analysed using a direct content approach and coded in NVivo. Findings The findings suggest that challenges may lie in the perception and understanding of statistics as well as short-term rather than long-term focus on improvement. The findings also suggest that academics and practitioners believe that Lean Six Sigma has developed over time and will continue to develop and improve as a methodology rather than being replaced with a new methodology. Research limitations/implications The survey has a sample size of 25, albeit all respondents are established and very experienced practitioners and academics. Practical implications For organisations that are introducing or refreshing their continuous improvement initiatives, this research identifies some of the challenges and provides the opportunity to address them to maximise the opportunities for success and sustainability. Originality/value The value of this paper is that it further addresses the debate over the integration of Lean and Six Sigma for many organisations which still employ Lean alone, but beyond this it explores how they will continue to develop and whether they are a permanent edition to the quality management landscape or a transition to something else.

scholarly journals Can compensation committees effectively mitigate the CEO horizon problem? The role of co-opted directors

2020 ◽  
Vol 34 (1) ◽  
pp. 1-21
Author(s):  
Ruonan Liu
Keyword(s):  
Corporate Governance ◽  
Research And Development ◽  
Empirical Evidence ◽  
Design Methodology ◽  
Ceo Compensation ◽  
Content Type ◽  
Horizon Problem ◽  
Accruals Management ◽  
Compensation Committees

Purpose This study aims to examine whether compensation committees dominated by co-opted directors are less effective in mitigating the CEO horizon problem. Design/methodology/approach The author uses a sample of 7,280 firm-year observations from 1998 to 2011. Findings In this study, the author finds evidence of opportunistic research and development (R&D) reduction and accruals management in firms with retiring CEOs and compensation committees dominated by co-opted directors. Moreover, it is found that R&D reduction and income-increasing accruals are less discouraged when determining the compensation for retiring CEOs by compensation committees that are dominated by co-opted directors. The results suggest that compensation committees dominated by co-opted directors are less effective in adjusting CEO compensation to mitigate the CEO horizon problem. Originality/value The study reveals that co-opted directors are weak monitors. Moreover, the study adds empirical evidence to the debate of organizations’ CEO horizon problem. Finally, the study adds to the literature on corporate governance, revealing that compensation committees play an important role in mitigating an organization’s CEO horizon problem by adjusting CEO compensation.

Smooth geometry generation in additive manufacturing file format: problem study and new formulation

2017 ◽  
Vol 23 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Kai-Ming Yu ◽  
Yu Wang ◽  
Charlie C.L. Wang
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Hermite Interpolation ◽  
File Format ◽  
Opposite Edge ◽  
Standard Specification ◽  
Content Type ◽  
New Formulation ◽  
Boundary Curves ◽  
Boolean Sum

Purpose In the newly released ASTM standard specification for additive manufacturing file (AMF) format – version 1.1 – Hermite curve-based interpolation is used to refine input triangles to generate denser mesh with smoother geometry. This paper aims to study the problems of constructing smooth geometry based on Hermite interpolation on curves and proposes a solution to overcome these problems. Design/methodology/approach A formulation using triangular Bézier patch is proposed to generate smooth geometry from input polygonal models. Different configurations on the boundary curves in the formulation are analyzed to further enrich this formulation. Findings The study shows that the formulation given in the AMF format (version 1.1) can lead to the problems of inconsistent normals and undefined end-tangents. Research limitations/implications The scheme has requirements on the input normals of a model, only C0 interpolation can be generated on those cases with less-proper input. Originality/value To overcome the problems of smooth geometry generation in the AMF format, the authors propose an enriched scheme for computing smooth geometry by using triangular Bézier patch. For the configurations with less-proper input, the authors adopt the Boolean sum and the Nielson’s point-opposite edge interpolation for triangular Coons patch to generate the smooth geometry as a C0 interpolant.

Barriers in adoption of additive manufacturing in medical sector supply chain

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Neha Choudhary ◽  
Anish Kumar ◽  
Varun Sharma ◽  
Pradeep Kumar
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Manufacturing Sector ◽  
Extensive Literature ◽  
Content Type ◽  
Potential Barriers ◽  
Organizational Barriers ◽  
Medical Sector ◽  
Network Process ◽  
And Training

PurposeAdditive manufacturing (AM) is expected to significantly transform the operations in manufacturing sector. It is also proposed to have optimistic applications in the medical supply chains (SC). However, its adoption in medical sector is faced with a range of barriers. Motivated by the need to establish an AM-based medical SC in a developing economy, the present paper analyses the potential barriers that would hinder the adoption of AM in medical SC.Design/methodology/approachBased on an extensive literature review and expert discussions, 12 significant barriers have been identified, which are analysed using an integrated interpretive structural modelling–analytical network process (ISM–ANP) methodology. An interrelationship between these barriers using ISM has been analysed to determine the driving-dependence power of these barriers using MICMAC (Matrice d' Impacts Croises-Multiplication Applique' e a' Classement) analysis. The barriers are then ranked using the ANP approach.FindingsIt has been focussed that the non-availability of a variety of materials, lack of education and training to designers and workers and production technology limitation are the most critical barriers. The results suggest that the managers should give greater significance to the technological and organizational barriers.Originality/valueAn approach to overcome these barriers can help the managers and organizations to develop successful AM-based SCs. The study is the first to identify and analyse the barriers for successful adoption of AM in medical SC context.

Maximizing design potential: investigating the effects of utilizing opportunistic and restrictive design for additive manufacturing in rapid response solutions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rohan Prabhu ◽  
Jordan Scott Masia ◽  
Joseph T. Berthel ◽  
Nicholas Alexander Meisel ◽  
Timothy W. Simpson
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Linear Models ◽  
Design For Additive Manufacturing ◽  
Content Type ◽  
Manufacturing Efficiency ◽  
Material Usage ◽  
Build Time ◽  
Rapid Prototyping And Manufacturing ◽  
Design For Am

Purpose The COVID-19 pandemic has resulted in numerous innovative engineering design solutions, several of which leverage the rapid prototyping and manufacturing capabilities of additive manufacturing. This paper aims to study a subset of these solutions for their utilization of design for AM (DfAM) techniques and investigate the effects of DfAM utilization on the creativity and manufacturing efficiency of these solutions. Design/methodology/approach This study compiled 26 COVID-19-related solutions designed for AM spanning three categories: (1) face shields (N = 6), (2) face masks (N = 12) and (3) hands-free door openers (N = 8). These solutions were assessed for (1) DfAM utilization, (2) manufacturing efficiency and (3) creativity. The relationships between these assessments were then computed using generalized linear models to investigate the influence of DfAM utilization on manufacturing efficiency and creativity. Findings It is observed that (1) unique and original designs scored lower in their AM suitability, (2) solutions with higher complexity scored higher on usefulness and overall creativity and (3) solutions with higher complexity had higher build cost, build time and material usage. These findings highlight the need to account for both opportunistic and restrictive DfAM when evaluating solutions designed for AM. Balancing the two DfAM perspectives can support the development of solutions that are creative and consume fewer build resources. Originality/value DfAM evaluation tools primarily focus on AM limitations to help designers avoid build failures. This paper proposes the need to assess designs for both, their opportunistic and restrictive DfAM utilization to appropriately assess the manufacturing efficiency of designs and to realize the creative potential of adopting AM.

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