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Article
Publication date: 5 December 2016

David O. Obada, Muhammad Dauda, Fatai O. Anafi, Abdulkarim S. Ahmed and Olusegun A. Ajayi

A structural and textural characterization study has been performed to investigate the adherence of zeolite-based catalyst washcoated onto honey-comb-type cordierite

Abstract

Purpose

A structural and textural characterization study has been performed to investigate the adherence of zeolite-based catalyst washcoated onto honey-comb-type cordierite monoliths. The supports were characterized by the scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) techniques.

Design/methodology/approach

SEM/EDS provided quantitative estimate of the washcoated monolith as the elemental composition of catalyst coating. The XRD pattern deduced that the zeolite-based catalysts were successfully mounted on the cordierite support, showing the characteristic peaks of zeolites (Zeolite Socony Mobil–5; ZSM-5) at Braggs angles of 7.88°, 8.76°, 23.04°, 23.88° and 24.36°, whereas the characteristic peak of cordierite is seen at a Braggs angle of 10.44°.

Findings

The BET results proved that a monolayer of zeolite may serve the need for surface area and porosity. This was evident in the increase of surface area of washcoated support as against the bare support. The obtained isotherms were of Type IV, illustrating the presence of mesopores. The adsorption and desorption isotherm branches coincided over the interval 0 < P/P0 < 0.50 and 0 < P/P0 < 0.45, showing N2 reversible adsorption for the two samples, respectively.

Originality/value

It was concluded that the composite materials which are ZSM-5 (Si/Al = 25) and precursors of the transition salts of copper, zinc and ceria powders were deposited on the catalyst supports, establishing the success of the coating procedure relative to the adherence of the catalyst compositions on the ceramic support.

Details

World Journal of Engineering, vol. 13 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 7 August 2017

Beata Synkiewicz, Dorota Szwagierczak and Jan Kulawik

The paper aims to report on fabrication procedure and present microstructure and dielectric behavior of multilayer porous low-temperature cofired ceramic (LTCC) structures…

Abstract

Purpose

The paper aims to report on fabrication procedure and present microstructure and dielectric behavior of multilayer porous low-temperature cofired ceramic (LTCC) structures based on glass-cordierite and glass-alumina.

Design/methodology/approach

The LTCC structures were created as multi-layered composites with dense external layers and inner layers with intentionally introduced porosity. Two preparation methods were applied – subsequent casting of both kinds of slurries and conventional isostatic lamination of dried green tapes arranged in the designed order. Optical microscope observations were carried out to analyze the microstructure of green and fired multilayer structures and pore concentration. To evaluate the adhesion strength of the composite layers, pull test was performed. Dielectric behavior of the composites was studied in the frequency range 50 kHz-2 MHz.

Findings

The fabricated porous LTCC structures showed dielectric constant of 3-5.6. The lowest dielectric constant was attained for glass-cordierite composite made by the conventional tape casting/lamination/firing method from slurry with 50 per cent graphite content. The samples prepared using multiple casting were of worse quality than those fabricated in conventional process, contained irregular porosity, showed tendency for deformation and delamination and exhibited a higher dielectric constant.

Originality/value

Search for new low dielectric constant materials applicable in LTCC technology and new methods of their fabrication is an important task for development of modern microwave circuits.

Details

Microelectronics International, vol. 34 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 April 1996

S.L. Fu, L.S. Chen and J.N. Lu

Substrate materials that can be sintered at temperatures lower than 1000°C have been prepared andstudied. The main compositions were achieved by adding low softening point…

Abstract

Substrate materials that can be sintered at temperatures lower than 1000°C have been prepared and studied. The main compositions were achieved by adding low softening point glasses to cordierite. A 96‐97% relative density can be obtained for cordierite to which 50‐60 wt % borosilicate glass is added. The dielectric constants are approximately 5.5‐6.5, and the loss tangents are below 2% at 1 MHz. Lamination of five layers of the aforementioned material tape‐cast into green tapes (40 mm × 40 mm) can be sintered into a single substrate (34 mm × 34 mm). In addition, the compatibility between the substrate material and the inner electrode and buried resistor material has also been studied.

Details

Microelectronics International, vol. 13 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 June 1987

S.G. TIMONEY, M.H. Farmer and D.A. Parker

An engine test rig has been designed and built for evaluation of monolithic ceramic components and metal components protected by ceramic shields or coatings for operation…

Abstract

An engine test rig has been designed and built for evaluation of monolithic ceramic components and metal components protected by ceramic shields or coatings for operation in the high temperature environment of the combustion gases of an uncooled diesel engine. Tests on the first monolithic ceramic components have shown thermal shock capability to be more critical than resistance to tensile bending, or vibration induced stresses. Configuration design can reduce the effects of the latter more readily than it can deal with thermal shock.

Details

Industrial Lubrication and Tribology, vol. 39 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 February 1986

Nihal Sinnadurai, G. Kersuzan, B.S. Sonde, Boguslaw Herod, Brian C. Waterfield, J.B. Knowles and M.A. Stein

I was an invited speaker to the ISHM‐Benelux meeting. As I arrived early, I also sat in on the committee meeting as an observer. Jos B. Peeters was the outgoing president…

Abstract

I was an invited speaker to the ISHM‐Benelux meeting. As I arrived early, I also sat in on the committee meeting as an observer. Jos B. Peeters was the outgoing president and the incoming committee was widened to about 15 members compared with the previous 6. Following the unanimous election of all those nominated, the committee reconvened and elected Mr Kwikkers as the new president of ISHM‐Benelux. He is a professor at the Technische Hogeschole in Delft.

Details

Microelectronics International, vol. 3 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 February 1994

B. Sjöling, S.P. Turvey and J.H. Alexander

Low temperature cofiring ceramic tape (LTCC) is increasingly used for the production of complex three‐dimensional multilayer interconnect structures in microelectronics…

Abstract

Low temperature cofiring ceramic tape (LTCC) is increasingly used for the production of complex three‐dimensional multilayer interconnect structures in microelectronics packaging. LTCC technology offers many attractive features including mechanical strength, high temperature performance, hermeticity and, with advanced crystallisable ceramic compositions, such as the Ferro A6 tape, outstanding microwave performance. Key among properties that discriminate LTCC technology from competing packaging approaches are two features that allow both design flexibility and maximum integratability: the ability to integrate the full range of passive components — resistors, capacitors and inductors — within the monolithic LTCC structure: and the fact that the LTCC interconnect system provides not only the interchip connection but also the package itself for the components, that is, the LTCC does not have to be placed in a further level of packaging before use. In this paper, the flexibility of design achievable with this company's A6 tape system including integratable passive components is discussed. Design rules that should be observed with the system to ensure that maximum benefit can be obtained from the key performance characteristics of the LTCC materials are addressed. Data supporting these design considerations are presented, as is a review of production processing parameters and their effect on yield, performance and cost of modules produced using the system. Specific project examples are reviewed to demonstrate the applications of this technology in advanced packaging design.

Details

Microelectronics International, vol. 11 no. 2
Type: Research Article
ISSN: 1356-5362

Abstract

Details

Urban Transport and the Environment
Type: Book
ISBN: 978-0-08-047029-0

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Article
Publication date: 1 September 2006

Marko Hrovat, Darko Belavič, Jaroslaw Kita, Janez Holc, Silvo Drnovšek, Jena Cilenšek, Leszek Golonka and Andrzej Dziedzic

Aims to evaluate different thick‐film materials for use in strain sensors and temperature sensors on low‐temperature co‐fired ceramic (LTCC) substrates.

Abstract

Purpose

Aims to evaluate different thick‐film materials for use in strain sensors and temperature sensors on low‐temperature co‐fired ceramic (LTCC) substrates.

Design/methodology/approach

LTCC materials are sintered at the low temperatures typically used for thick‐film processing, i.e. around 850°C, The thick‐film resistor materials for use as strain and temperature sensors on LTCC tapes are studied. Thick‐film piezo‐resistors in the form of strain‐gauges are realised with 10 kΩ/sq. 2041 (Du Pont)and 3414‐B (ESL), resistor materials; thick‐film temperature‐dependent resistors were made from PTC 5093 (Du Pont), and NTC‐4993 (EMCA Remex) resistor materials.

Findings

The X‐ray spectra of the 2041 and 3414‐Bb low TCR resistors after drying at 150°C and after firing display more or less the same peaks. The electrical characteristics of 2041 resistors fired on alumina and LTCC substrates are similar indicating that the resistors are compatible with the LTCC material. After firing on LTCC substrates the sheet resistivities and TCRs of the 3414‐B resistors increased. Also, there is a significant increase in the GFs from 13 to over 25.

Originality/value

Investigates the compatibility of thick‐film materials and the characteristics of the force and temperature sensors.

Details

Microelectronics International, vol. 23 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 January 1987

Eighty‐five participants attended the 4th ISHM Display meeting at the Jaarbeurs Congress Centre in Utrecht on 16 October, 1986. The programme of the day started with the…

Abstract

Eighty‐five participants attended the 4th ISHM Display meeting at the Jaarbeurs Congress Centre in Utrecht on 16 October, 1986. The programme of the day started with the annual general membership meeting of the Benelux Chapter. The chairman, Mr T. Kwikkers, gave a short review of the state of affairs of ISHM‐Benelux and of the activities of the last year. He mentioned the temporary enlargement of the executive committee to give a new generation a chance to gain experience in the ISHM organisation and to take up some new activities. In order to raise publicity for ISHM and Hybrid Circuits a new brochure has been designed and a set of material for demonstration purposes was collected. With the material every member of the chapter can easily set up a presentation for schools or customers. This year ISHM‐Benelux has grown from 85 to 100 members and enjoys a healthy financial situation. Next year again emphasis will be put on public relations. Professor R. Govaerts signified that he was no longer available for a position in the executive committee. As Prof. Govaerts has been very active and stimulating for the ISHM‐Benelux Chapter from its foundation in 1976 up to now, the general membership meeting decided to appoint him as (the first) honorary member of this chapter. Except for Professor Govaerts, the sitting executive committee, consisting of 15 members, was re‐elected for another year. After the European conferences in Bournemouth and Hamburg the ISHM‐Benelux chapter is asked to organise the 1991 Conference. The executive committee is already looking out for candidates for a function in the organising committee, which must be formed in the coming year.

Details

Microelectronics International, vol. 4 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 10 October 2018

Tugdual Amaury Le Néel, Pascal Mognol and Jean-Yves Hascoët

The purpose of this paper is to analyze the current state of the art manufacturing techniques using sand molds for the casting industry by the means of additive…

Abstract

Purpose

The purpose of this paper is to analyze the current state of the art manufacturing techniques using sand molds for the casting industry by the means of additive manufacturing (AM). In particular, this review will cover two families of 3D printing in regards to sand mold fabrication.

Design/methodology/approach

This paper will discuss the sand casting manufacturing processes of AM by binder jetting (3D printing) and selective laser sintering. Scientific articles, patents and case studies are analyzed. Topics ranging from the technology types to the economic implications are covered.

Findings

The review investigates new factors and methods for mold design, looking at mechanical properties and cost analysis as influenced by material selection, thermal characteristics, topological optimization and manufacturing procedure. Findings in this study suggest that this topic lacks vigorous scientific research and that the case studies by manufacturers thus far are not useful.

Research limitations/implications

As demonstrated by the limited data from previous published studies, a more comprehensive and conclusive analysis is needed due to the lack of interest and resources regarding the AM of sand molds.

Practical implications

This study is a useful tool for any researchers with an interest in the field of AM of sand molds.

Social implications

Key perspectives are proposed.

Originality/value

This review highlights current gaps in this field. The review goes beyond the scientific articles by curating patents and professional case studies.

Details

Rapid Prototyping Journal, vol. 24 no. 8
Type: Research Article
ISSN: 1355-2546

Keywords

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