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Article
Publication date: 1 March 2001

B.G. Bryden, D.I. Wimpenny and I.R. Pashby

Lastform, a three year EPSRC (IMI) programme, has investigated metallic laminating techniques to produce large‐scale production capable tooling. This work is intended as an…

1124

Abstract

Lastform, a three year EPSRC (IMI) programme, has investigated metallic laminating techniques to produce large‐scale production capable tooling. This work is intended as an overview of the research and development performed at the University of Warwick’s Warwick manufacturing Group. The programme was a collaboration between seven industrial partners and three universities with each university having a discreet area of research. The focus at Warwick was to establish robust methods of joining metal sheets to form tools for different production processes. Bonding mediums, test parts for process evaluation, sample tools and production tools are described. The advantages of metal laminating for different processes are evaluated. Results include reduced lead‐time and cost savings and enhanced processing capability by the use of conformable heating or cooling channels.

Details

Rapid Prototyping Journal, vol. 7 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 14 October 2020

Aldi Mehmeti, Pavel Penchev, Donal Lynch, Denis Vincent, Nathalie Maillol, Johannes Maurath, Julien Bajolet, David Ian Wimpenny, Khamis Essa and Stefan Dimov

The paper reports an investigation into the mechanical behaviour of hybrid components produced by combining the capabilities of metal injection moulding (MIM) with the laser-based…

259

Abstract

Purpose

The paper reports an investigation into the mechanical behaviour of hybrid components produced by combining the capabilities of metal injection moulding (MIM) with the laser-based powder bed fusion (PBF) process to produce small series of hybrid components. The research investigates systematically the mechanical properties and the performance of the MIM/PBF interfaces in such hybrid components.

Design/methodology/approach

The MIM process is employed to fabricate relatively lower cost preforms in higher quantities, whereas the PBF technology is deployed to build on them sections that can be personalised, customised or functionalised to meet specific technical requirements.

Findings

The results are discussed, and conclusions are made about the mechanical performance of such hybrid components produced in batches and also about the production efficiency of the investigated hybrid manufacturing (HM) route. The obtained results show that the proposed HM route can produce hybrid MIM/PBF components with consistent mechanical properties and interface performance which comply with the American Society for Testing and Materials (ASTM) standards.

Originality/value

The manufacturing of hybrid components, especially by combining the capabilities of additive manufacturing processes with cost-effective complementary technologies, is designed to be exploited by industry because they can offer flexibility and cost advantages in producing small series of customisable products. The findings of this research will contribute to further develop the state of the art in regards to the manufacturing and optimisation of hybrid components.

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Article
Publication date: 19 January 2015

Jason B. Jones, David I. Wimpenny and Greg J Gibbons

This paper aims to investigate the effects on material properties of layer-by-layer application of pressure during fabrication of polymeric parts by additive manufacturing (AM)…

1661

Abstract

Purpose

This paper aims to investigate the effects on material properties of layer-by-layer application of pressure during fabrication of polymeric parts by additive manufacturing (AM). Although AM, also known popularly as 3D printing, has set a new standard for ease of use and minimal restraint on geometric complexity, the mechanical part properties do not generally compare with conventional manufacturing processes. Contrary to other types of polymer processing, AM systems do not normally use (in-process) pressure during part consolidation.

Design/methodology/approach

Tensile specimens were produced in Somos 201 using conventional laser sintering (LS) and selective laser printing (SLP) – a process under development in the UK, which incorporates the use of pressure to assist layer consolidation.

Findings

Mechanical testing demonstrated the potential to additively manufacture parts with significantly improved microstructure and mechanical properties which match or exceed conventional processing. For example, the average elongation at break and ultimate tensile strength of a conventionally laser-sintered thermoplastic elastomer (Somos 201) increased from 136 ± 28 per cent and 4.9 ± 0.4 MPa, to 513 ± 35 per cent and 10.4 ± 0.4 MPa, respectively, when each layer was fused with in-process application of pressure (126 ± 9 kPa) by SLP.

Research limitations/implications

These results are based on relatively small sample size, but despite this, the trends observed are of significant importance to the elimination of voids and porosity in polymeric parts.

Practical implications

Layerwise application of pressure should be investigated further for defect elimination in AM.

Originality/value

This is the first study on the effects of layerwise application of pressure in combination with area-wide fusing.

Details

Rapid Prototyping Journal, vol. 21 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 October 2000

David Ian Wimpenny and Gregory John Gibbons

This work was performed within IMI Spray Mould, an EPSRC joint funded programme, aimed at developing a manufacturing route for large aerospace composite forming tooling, based on…

1004

Abstract

This work was performed within IMI Spray Mould, an EPSRC joint funded programme, aimed at developing a manufacturing route for large aerospace composite forming tooling, based on metal spray technologies. Assesses the mechanical properties of Invar steel coatings, deposited using electric arc spraying, and correlates these properties to the spray parameters and processes used so as to offer coatings with characteristics appropriate to the tooling requirements. In particular, two processing methods, inert and air atomisation, and three arc spray gun configurations (air cap design) are evaluated. The mechanical properties of the coatings are found to be low compared to bulk Invar, regardless of the spray parameters and hardware used. Inert arc spraying affords more consistent coating characteristics but this comes with a compromised durability. The spray hardware is found to be more significant in determining the coating properties than the parameters employed.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 5
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 27 January 2021

Irina Tatiana Garces and Cagri Ayranci

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the…

1142

Abstract

Purpose

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the limitations and possible improvements in the different research areas within the different AM techniques. The purpose of this study is to identify academic and industrial opportunities.

Design/methodology/approach

This paper introduces the reader to three-dimensional (3 D) and four-dimensional printing of shape memory polymers (SMPs). Specifically, this review centres on manufacturing technologies based on material extrusion, photopolymerization, powder-based and lamination manufacturing processes. AM of SMPC was classified according to the nature of the filler material: particle dispersed, i.e. carbon, metallic and ceramic and long fibre reinforced materials, i.e. carbon fibres. This paper makes a distinction for multi-material printing with SMPs, as multi-functionality and exciting applications can be proposed through this method. Manufacturing strategies and technologies for SMPC are addressed in this review and opportunities in the research are highlighted.

Findings

This paper denotes the existing limitations in the current AM technologies and proposes several directions that will contribute to better use and improvements in the production of additive manufactured SMPC. With advances in AM technologies, gradient changes in material properties can open diverse applications of SMPC. Because of multi-material printing, co-manufacturing sensors to 3D printed smart structures can bring this technology a step closer to obtain full control of the shape memory effect and its characteristics. This paper discusses the novel developments in device and functional part design using SMPC, which should be aided with simple first stage design models followed by complex simulations for iterative and optimized design. A change in paradigm for designing complex structures is still to be made from engineers to exploit the full potential of additive manufactured SMPC structures.

Originality/value

Advances in AM have opened the gateway to the potential design and fabrication of functional parts with SMPs and their composites. There have been many publications and reviews conducted in this area; yet, many mainly focus on SMPs and reserve a small section to SMPC. This paper presents a comprehensive review directed solely on the AM of SMPC while highlighting the research opportunities.

Details

Rapid Prototyping Journal, vol. 27 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 October 2018

Matthew James Benning and Kenny Dalgarno

This paper aims to develop and then evaluate a novel consolidation and powder transfer mechanism for electrophotographic 3D printing, designed to overcome two longstanding…

222

Abstract

Purpose

This paper aims to develop and then evaluate a novel consolidation and powder transfer mechanism for electrophotographic 3D printing, designed to overcome two longstanding limitations of electrophotographic 3D printing: fringing and a build height limitation.

Design/methodology/approach

Analysis of the electric field generated within electrophotographic printing was used to identify the underlying causes of the fringing and build height limitations. A prototype machine was then designed and manufactured to overcome these limitations, and a number of print runs were carried out as proof of concept studies.

Findings

The analysis suggested that a machine design which separated the electrostatic powder deposition of the print engine from the layer transfer and consolidation steps is required to overcome fringing and build height limitations. A machine with this build architecture was developed and proof of concept studies showed that the build height and fringing effects were no longer evident.

Research limitations/implications

Electrophotography (EP) was initially seen as a promising technology for 3D printing, largely because the potential for multi-material printing at high speed. As these limitations can now be overcome, there is still potential for EP to deliver a high-speed 3D printing system which can build parts consisting of multiple materials.

Originality/value

The analysis of EP, the new method for the transfer and consolidation of layers and the proof of concept study are all original and provide new information on how EP can be adopted for 3D printing.

Details

Rapid Prototyping Journal, vol. 24 no. 6
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 December 2003

Gregory John Gibbons, Robert G. Hansell, A.J. Norwood and P.M. Dickens

This paper details the development of a rapid tooling manufacturing route for the gravity and high‐pressure die‐casting industries, resulting from an EPSRC funded collaborative…

1460

Abstract

This paper details the development of a rapid tooling manufacturing route for the gravity and high‐pressure die‐casting industries, resulting from an EPSRC funded collaborative research project between the Universities of Warwick, Loughborough and DeMontfort, with industrial support from, amongst others, MG Rover, TRW Automotive, Sulzer Metco UK Ltd and Kemlows Diecasting Products Ltd. The developed process offers the rapid generation of mould tools from laser‐cut laminated sheets of H13 steel, bolted or brazed together and finish machined. The paper discusses the down‐selection of materials, bonding methods and machining methods, the effect of conformal cooling channels on process efficiency, and the evaluation of a number of test tools developed for the industrial partners. The paper also demonstrates the cost and time advantages (up to 50 and 54 per cent, respectively) of the tooling route compared to traditional fabrication methods.

Details

Assembly Automation, vol. 23 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 5 June 2007

L‐E. Rännar, A. Glad and C‐G. Gustafson

The purpose of this paper is to present a comparative study, regarding cooling time and dimensional accuracy, of conventional injection mold cooling channel layouts, using…

3534

Abstract

Purpose

The purpose of this paper is to present a comparative study, regarding cooling time and dimensional accuracy, of conventional injection mold cooling channel layouts, using straight holes and a baffle, and free‐form fabricated (FFF) layout, manufactured by the direct‐metal rapid tooling (RT) method electron beam melting (EBM). Many other methods have been proven useful for RT, but the authors have not found any publications where EBM has been used to manufacture injection molding tools.

Design/methodology/approach

A test part was designed in order to replicate a common and important issue: inadequate cooling in deep cores. The part and the different cooling layouts were analyzed in an injection molding simulation software and the numerical results were compared with corresponding experimental results.

Findings

The analyses showed an improvement in both cooling time and dimensional accuracy in favor of conformal FFF cooling channels manufactured by EBM. The experimental results correlate well with the numerical tests, however with some discrepancies.

Research limitations/implications

The results presented are based on the direct‐metal RT method EBM, and they were obtained using a specific test part.

Originality/value

This paper can be a useful aid when designing mold tools and especially when considering the usage of FFF cooling channels versus conventional cooling design. It can also serve as a reference when comparing the efficiency in terms of cooling time and dimensional accuracy between different layouts.

Details

Rapid Prototyping Journal, vol. 13 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 8 June 2012

K.P. Karunakaran, Alain Bernard, S. Suryakumar, Lucas Dembinski and Georges Taillandier

The purpose of this paper is to review additive and/or subtractive manufacturing methods for metallic objects and their gradual evolution from prototyping tools to rapid…

3830

Abstract

Purpose

The purpose of this paper is to review additive and/or subtractive manufacturing methods for metallic objects and their gradual evolution from prototyping tools to rapid manufacture of actual parts.

Design/methodology/approach

Various existing rapid manufacturing (RM) methods have been classified into six groups, namely, CNC machining laminated manufacturing, powder‐bed technologies, deposition technologies, hybrid technologies and rapid casting technologies and discussed in detail. The RM methods have been further classified, based on criteria such as material, raw material form, energy source, etc. The process capabilities springing from these classifications are captured in the form of a table, which acts as a database.

Findings

Due to the approximation in RM in exchange for total automation, a variety of multi‐faceted and hybrid approaches has to be adopted. This study helps in choosing the appropriate RM process among these myriad technologies.

Originality/value

This review facilitates identification of appropriate RM process for a given situation and sets the framework for design for RM.

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Article
Publication date: 25 October 2021

Yanen Wang, Ray Tahir Mushtaq, Ammar Ahmed, Ammar Ahmed, Mudassar Rehman, Mudassar Rehman, Aqib Mashood Khan, Shubham Sharma, Dr Kashif Ishfaq, Haider Ali and Thierno Gueye

Additive manufacturing (AM) technology has a huge influence on the real world because of its ability to manufacture massively complicated geometrics. The purpose of this study is…

485

Abstract

Purpose

Additive manufacturing (AM) technology has a huge influence on the real world because of its ability to manufacture massively complicated geometrics. The purpose of this study is to use CiteSpace (CS) visual analysis to identify fused deposition modeling (FDM) research and development patterns to guide researchers to decide future research and provide a framework for corporations and organizations to prepare for the development in the rapid prototyping industry. Three-dimensional printing (3DP) is defined to budget minimize manufactured input and output for aviation and the medical product industrial sectors. 3DP has implemented its potential in the Coronavirus Disease of 2019 (COVID-19) reaction.

Design/methodology/approach

First, 396 original publications were extracted from the web of science (WOS) with the comprehensive list and did scientometrics analysis in CS software. The parameters are specified in CS including the span (from 2011 to 2019, one year slice for the co-authorship and the co-accordance analysis), visualization (show the merged networks), specific criteria for selection (top 20%), node form (author, organization, region, reference cited; cited author, journal and keywords) and pruning (pathfinder and slicing network). Finally, correlating data was studied and showed the results of the visualization study of FDM research were shown.

Findings

The framework of FDM information is beginning to take shape. About hot research topics, there are “Morphology,” “Tensile Property by making Blends,” “Use of Carbon nanotube in 3DP” and “Topology optimization.” Regarding the latest research frontiers of FDM printing, there are “Fused Filament Fabrication,” “AM,” in FDM printing. Where “Post-processing” and “environmental impact” are the research hotspots in FDM printing. These research results can provide insight into FDM printing and useful information to consider the existing studies and developments in FDM researchers’ analysis.

Research limitations/implications

Despite some important obtained results through FDM-related publications’ visualization, some deficiencies remain in this research. With >99% of articles written in English, the input data for CS was all downloaded from WOS databases, resulting in a language bias of papers in other languages and neglecting other data sources. Although, there are several challenges being faced by the FDM that limit its wide variety of applications. However, the significance of the current work concerning the technical and engineering prospects is discussed herein.

Originality/value

First, the novelty of this work lies in describing the FDM approach in a Scientometric way. In Scientometric investigation, leading writers, organizations, keywords, hot research and emerging knowledge points were explained. Second, this research has thoroughly and comprehensively examined the useful sustainability effects, i.e. economic sustainability, energy-based sustainability, environmental sustainability, of 3DP in industrial development in qualitative and quantitative aspects by 2025 from a global viewpoint. Third, this work also described the practical significance of FDM based on 3DP since COVID-19. 3DP has stepped up as a vital technology to support improved healthcare and other general response to emergency situations.

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