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Article
Publication date: 1 September 1998

Suman Das, Joseph J. Beama, Martin Wohlert and David L. Bourell

This paper focuses on recent advances in direct freeform fabrication of high performance components via selective laser sintering (SLS). The application, known as SLS/HIP…

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2862

Abstract

This paper focuses on recent advances in direct freeform fabrication of high performance components via selective laser sintering (SLS). The application, known as SLS/HIP, is a low cost manufacturing technique that combines the strengths of selective laser sintering and hot isostatic pressing (HIP) to rapidly produce low volume or “one of a kind” high performance metal components. Direct selective laser sintering is a rapid manufacturing technique that can produce high density metal parts of complex geometry with an integral, gas impermeable skin. These parts can then be directly post‐processed by containerless HIP. The advantages of in situ encapsulation include elimination of a secondary container material and associated container‐powder interaction, reduced pre‐processing time, a short HIP cycle and reduction in post‐processing steps compared to HIP of canned parts. SLS/HIP is currently being developed under a DARPA/ONR program for INCONEL® 625 superalloy and Ti‐6Al‐4V, the demonstration components being the F‐14 turbine engine vane and the AIM‐9 missile guidance section housing base respectively.

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Rapid Prototyping Journal, vol. 4 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 June 2000

B. Engel and D.L. Bourell

Selective laser sintering (SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The processability of metal powder…

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2016

Abstract

Selective laser sintering (SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The processability of metal powder varies depending on the state of the powder prior to SLS. A powder thermal pre‐treatment was developed which involved degassing the powder at an elevated temperature in a vacuum. Without powder thermal pre‐treatment, the powder may flow poorly and may “ball” or form molten clumps during the laser exposure rather than wetting into the present and previous layer. These effects result in SLS parts with poor surface finish, mechanical properties and density. The purpose of this study was to identify for titanium alloy powder the mechanisms responsible for the improvements obtained after powder thermal pre‐treatment and to optimize the thermal excursion.

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Rapid Prototyping Journal, vol. 6 no. 2
Type: Research Article
ISSN: 1355-2546

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Content available
Book part
Publication date: 14 March 2017

Kenneth M. Moffett

Abstract

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Forming and Centering
Type: Book
ISBN: 978-1-78635-829-5

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Book part
Publication date: 14 March 2017

Kenneth M. Moffett

Abstract

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Forming and Centering
Type: Book
ISBN: 978-1-78635-829-5

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Article
Publication date: 13 February 2009

Vickie Cox Edmondson, Gouri Gupte, Rexford H. Draman and Nathan Oliver

This paper aims to discuss the importance of organisations paying closer attention to their corporate language policies as a strategy for embracing diversity in their workforce.

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9196

Abstract

Purpose

This paper aims to discuss the importance of organisations paying closer attention to their corporate language policies as a strategy for embracing diversity in their workforce.

Design/methodology/approach

An exploratory study of the web sites of companies recognized for their diversity efforts is conducted to highlight their communication strategy, in particular the terminology used to refer to non‐whites.

Findings

This research found that the language used in corporate communications to refer to non‐whites varies even among companies that have been highly recognized for their diversity efforts. While the web sites clearly revealed the companies' commitment to diversity, the difficulty associated with this controversial issue can also be seen. An argument is made that organisations should eliminate the use of the term “minority” from their communications in an effort to enhance their diversity climate and more accurately reflect their commitment to diversity.

Research limitations/implications

This research relied on web site content analysis and only the sites of companies that have been highly recognized for their diversity efforts were considered.

Practical implications

The paper shows that as the debate about the use of the term “minorities” continues, companies that embrace diversity should pay close attention to the language used in their corporate communications to ensure that the messages and signals they send consistently mirror their beliefs and perceptions of various stakeholders.

Originality/value

This research may be of special interest to communication strategists and persons within the organisation that are interested in improving their corporate image and addressing the behaviours and attitudes of the organisation's stakeholders.

Details

Journal of Communication Management, vol. 13 no. 1
Type: Research Article
ISSN: 1363-254X

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Article
Publication date: 24 February 2012

Melanie Bull and Tim Brown

Communication is fundamental to the facilities management (FM) role within organisations; especially when the FM department is implementing changes to the workplace. This…

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9179

Abstract

Purpose

Communication is fundamental to the facilities management (FM) role within organisations; especially when the FM department is implementing changes to the workplace. This paper aims to present an evaluation of an instance.

Design/methodology/approach

A self‐administered online questionnaire was used to collect quantitative and qualitative data. The research focused on responses to satisfaction with the communication methods rather than reviewing the merits of alternative workplace strategies.

Findings

Findings included the impact of communication on staff satisfaction levels, the need to provide timely and relevant information and communication via a range of mediums and the need to ensure there was opportunity to participate in meaningful feedback. The key findings are substantiated with existing internal communication and change literature.

Originality/value

The research highlights the practical importance of the need to improve communication within the FM industry and especially in change circumstances.

Details

Facilities, vol. 30 no. 3/4
Type: Research Article
ISSN: 0263-2772

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Article
Publication date: 5 June 2020

Lai Jiang, Xiaobo Peng and Daniel Walczyk

This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing…

Abstract

Purpose

This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing technologies, including powder-based, material extrusion, solid-sheet and liquid-based systems. Detailed information about each process, including materials used and process design, are described, with the resultant products’ mechanical properties compared with those of 3D-printed parts produced from pure resin or different material combinations. In most processes introduced in this paper, biofibers are beneficial in improving the mechanical properties of 3D-printed parts and the biodegradability of the parts made using these green materials is also greatly improved. However, research on 3D printing of biofiber-reinforced composites is still far from complete, and there are still many further studies and research areas that could be explored in the future.

Design/methodology/approach

The paper starts with an overview of the current scenario of the composite manufacturing industry and then the problems of advanced composite materials are pointed out, followed by an introduction of biocomposites. The main body of the paper covers literature reviews of recently emerged 3D printing technologies that were applied to biofiber-reinforced composite materials. This part is classified into subsections based on the form of the starting materials used in the 3D printing process. A comprehensive conclusion is drawn at the end of the paper summarizing the findings by the authors.

Findings

Most of the biofiber-reinforced 3D-printed products exhibited improved mechanical properties than products printed using pure resin, indicating that biofibers are good replacements for synthetic ones. However, synthetic fibers are far from being completely replaced by biofibers due to several of their disadvantages including higher moisture absorbance, lower thermal stability and mechanical properties. Many studies are being performed to solve these problems, yet there are still some 3D printing technologies in which research concerning biofiber-reinforced composite parts is quite limited. This paper unveils potential research directions that would further develop 3D printing in a sustainable manner.

Originality/value

This paper is a summary of attempts to use biofibers as reinforcements together with different resin systems as the starting material for 3D printing processes, and most of the currently available 3D printing techniques are included herein. All of these attempts are solutions to some principal problems with current 3D printing processes such as the limit in the variety of materials and the poor mechanical performance of 3D printed parts. Various types of biofibers are involved in these studies. This paper unveils potential research directions that would further widen the use of biofibers in 3D printing in a sustainable manner.

Details

Rapid Prototyping Journal, vol. 26 no. 6
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 20 June 2017

Chor Yen Yap, Hongyi Kenneth Tan, Zhenglin Du, Chee Kai Chua and Zhili Dong

Selective laser melting (SLM) is an additive manufacturing technology that is gaining industrial and research interest as it can directly fabricate near full density…

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760

Abstract

Purpose

Selective laser melting (SLM) is an additive manufacturing technology that is gaining industrial and research interest as it can directly fabricate near full density metallic components. The paper aims to identify suitable process parameters for SLM of processing of pure nickel powder and to study the microstructure of such products. The study also aims to characterize the microhardness and tensile properties of pure nickel produced by SLM.

Design/methodology/approach

A 24 factorial design experiment was carried out to identify the most significant factors on the resultant porosity of nickel parts. A subsequent experiment was carried out with a laser power of 350 W. The scanning speeds and hatch spacings were varied.

Findings

Scanning speed and hatch spacing have significant effects on the porosity of SLM components. A high relative density of 98.9 per cent was achieved, and microhardness of 140 to 160 Hv was obtained from these samples. A tensile strength 452 MPa was obtained.

Research limitations/implications

As the energy input levels were made in steps of 20 J/mm3 for the optimization study, the true optimal combination of parameters may have been missed. Therefore, researchers are encouraged to test the parameters with smaller variations in energy levels.

Practical implications

The paper provides a set of optimized parameters for the SLM of pure nickel. This study enables the three-dimensional (3D) printing of objects with nickel, which has applications in chemical catalyses and in microelectromechanical systems with its magnetostrictive properties.

Originality value

This research is the first in direct processing of pure nickel using SLM, with the identification of suitable process parameters. The study also provides an understanding of the porosity, microhardness, strength and microstructure of SLM produced nickel parts. This work paves the way for standardization of 3D printed nickel components and enables the applications of pure nickel via SLM.

Details

Rapid Prototyping Journal, vol. 23 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

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