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Article
Publication date: 1 January 1962

D.M. Grounds

In recent years there has been a substantial increase in the number of Engineering students who are studying Metallurgy. Considerable thought has been given to the…

Abstract

In recent years there has been a substantial increase in the number of Engineering students who are studying Metallurgy. Considerable thought has been given to the syllabus content offered to these students both by metallurgists and engineers, but the writer felt that a direct approach to the students themselves may provide some interesting results. With this aim in view a questionnaire was prepared and sent out, together with an explanatory letter, to every Engineering student who had taken Metallurgy at the South‐East Essex Technical College since September 1957, i.e. four academic years. The number of students totalled 328 and of these exactly 50 per cent returned their completed questionnaire. This it was considered was an acceptable statistical sample. The answers given have all been carefully analysed and the results noted, and from these we have endeavoured to draw some general conclusions.

Details

Education + Training, vol. 4 no. 1
Type: Research Article
ISSN: 0040-0912

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Article
Publication date: 1 August 2002

C.H. Zhong, S. Yi and D.C. Whalley

Plastic ball grid array packages were aged for up to 2000 hours. Various solder ball pad metallurgies were studied and solder ball shear tests were conducted at a range of…

Abstract

Plastic ball grid array packages were aged for up to 2000 hours. Various solder ball pad metallurgies were studied and solder ball shear tests were conducted at a range of ageing times. The solder ball shear strength was found to decrease after an initial hardening stage. The deterioration of solder ball shear strength was found to be mainly caused by the formation of intermetallic compound layers, together with microstructural coarsening and diffusion related porosity at the interface. For the ball pad metallurgy, two distinct intermetallic compound layer structures were observed to have formed after ageing. Once two continuous intermetallic compound layers formed fracture tended to occur at their interface. For the ball pad metallurgies which do not form two continuous intermetallic compound layers, the shear strength still decreased, due to the coarsening of the microstructure, intermetallic particle formation and diffusion related porosity at the surface of the Ni3Sn4.

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Soldering & Surface Mount Technology, vol. 14 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 May 1964

LL Shreir

Corrosion studies in the department of metallurgy COURSES in various aspects of metallurgy have been provided by the Sir John Cass College since its foundation as a…

Abstract

Corrosion studies in the department of metallurgy COURSES in various aspects of metallurgy have been provided by the Sir John Cass College since its foundation as a technical institute in 1902, and in 1928 the Department of Metallurgy commenced systematic courses leading to the B.Sc.(Eng.) degree in metallurgy of the University of London. It is true to say that the syllabus for this degree has largely determined the pattern of metallurgical interests in the department and as little emphasis was placed on corrosion, the subject was naturally neglected.

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Anti-Corrosion Methods and Materials, vol. 11 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 October 1960

G.B. Clarke

In his inaugural lecture at Imperial College, Professor J. G. Ball pointed to the tendency of metallurgy to become a scientific discipline of logical inference, making…

Abstract

In his inaugural lecture at Imperial College, Professor J. G. Ball pointed to the tendency of metallurgy to become a scientific discipline of logical inference, making teaching centred on plant skills, and the parrot‐learning of facts and alloy specifications quite out of date. The principles and practice of teaching with special reference to metallurgy have not received the attention accorded to allied subjects such as chemistry. The purpose of this article is to provoke thought, criticism and free discussion among those engaged in the dissemination of metallurgical knowledge.

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Education + Training, vol. 2 no. 10
Type: Research Article
ISSN: 0040-0912

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Article
Publication date: 1 March 1944

W.D. Jones

THE moulded plastics industry has in the last few years, both in engineering and domestic directions, encroached upon the traditional fields of the metallurgist and it is…

Abstract

THE moulded plastics industry has in the last few years, both in engineering and domestic directions, encroached upon the traditional fields of the metallurgist and it is now very noticeable even to the layman the extent to which all sorts of articles are made from plastics which were previously fashioned from metal castings or pressings. The metal‐lurgist is now, however, providing his reply by stealing the very essentials of the plastics technique and applying it to the moulding of metals. This technique of Powder Metallurgy broadly consists in taking a metal or alloy, or mixtures of metals or alloys, powdered to something similar to the consistency of flour and pressing it in a die under pressures varying from 5 to 50 tons sq. in. From the press is ejected a green compact which is then heat treated in a protective atmosphere at a temperature of approximately two‐thirds of the melting point of the alloy concerned. The product may be broadly classified into three types according to its qualities: (a) It may closely resemble normal cast or forged metals although generally possessing inferior, but not substantially inferior, physical qualities. In this field powder metallurgy becomes no more than another method of manufacturing metallic articles and finds its chief application where machining costs can be avoided. For example a start has been made in this country in the manufacture of small steel gears, almost equal in quality but appreciably cheaper than a machine‐cut gear. The powder metallurgy technique is able to handle a much wider range of alloys' than are customary in die casting (steels, heat‐resisting alloys, nickel, tungsten for example) but is much more limited in shape design. Broadly only those articles can be manufactured which are of a simple directly pressable shape without undercut surfaces. (b) It may be porous. The porosity can generally vary from 5 to 60 per cent by volume and the size of the pores from one millimetre in diameter to a porosity scarcely visible under the microscope. Porous bronzes saturated with oil have been in use for a number of years, particularly in circumstances where normal bearing lubrication is difficult, such as in refrigerators, vacuum cleaners, sewing machines and clocks, but the war has seen an enormous application of them in aircraft and tanks. Newer uses for porous metals are frequently being discovered and they have already extensive applications as oil, chemical and gas filters. (c) It may have qualities which are unobtainable in any other manner. Forged or cast metals are after all physically constructed with only those constituents which can be crystallized from a molten metal and this is a very severe limitation. By powder metallurgy this phase from this alloy and that from that alloy can be agglomerated into a mass having new physical properties; together, if desirable, with suitable non‐metallic materials. Powder metallurgy as a technique therefore has exten sive possibilities in providing new synthetic metallic materials. At the present time cemented carbide cutting tools, electrical contacts, impregnated diamond tools and friction surfaces are typical examples of this class and indicate something of what the future offers.

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Aircraft Engineering and Aerospace Technology, vol. 16 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 26 July 2018

Saravanan C., Subramanian K., Anandakrishnan V. and Sathish S.

Aluminium is the most preferred material in engineering structural components because of its excellent properties. Furthermore, the properties of aluminium may be enhanced…

Abstract

Purpose

Aluminium is the most preferred material in engineering structural components because of its excellent properties. Furthermore, the properties of aluminium may be enhanced through metal matrix composites and an in-depth investigation on the evolved properties is needed in view of metallurgical, mechanical and tribological aspects. The purpose of this study is to explore the effect of TiC addition on the tribological behavior of aluminium composites.

Design/methodology/approach

Aluminium metal matrix composites at different weight percentage of titanium carbide were produced through powder metallurgy. Produced composites were subjected to sliding wear test under dry condition through Taguchi’s L9 orthogonal design.

Findings

Optimal process condition to achieve the minimum wear rate was identified though the main effect plot. Sliding velocity was identified as the most dominating factor in the wear resistance.

Practical implications

The production of components with improved properties is promoted efficiently and economically by synthesizing the composite via powder metallurgy.

Originality/value

Though the investigations on the wear behavior of aluminium composites are analyzed, reinforcement types and the mode of fabrication have their significance in the metallurgical and mechanical properties. Thus, the produced component needs an in-detail study on the property evolution.

Details

Industrial Lubrication and Tribology, vol. 70 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 March 2017

Omid Pourali, Hashem Ghasemi Kadijani and Farideh Mohammadi Khangheshlaghi

An effective chemical conditioning technique was successfully tested and investigated to control and minimize the chemistry-related damages within mixed metallurgy steam…

Abstract

Purpose

An effective chemical conditioning technique was successfully tested and investigated to control and minimize the chemistry-related damages within mixed metallurgy steam and water cycle of Heller dry cooled combined cycle power plants (CCPPs), in which cooling water and condensate are completely mixed in direct contact condenser. This study aims to perform a comprehensive experimental research in four mixed metallurgy steam and water cycle.

Design/methodology/approach

A comprehensive experimental study was carried out in four mixed metallurgy steam and water cycle fabricated with ferrous- and aluminum-based alloys which have various corrosion resistance capabilities in contact with water. Chemical conditioning was conducted using both volatile and non-volatile alkalizing agents, and, to perform chemical conditioning effectively, quality parameters (pH, conductivity, dissolved oxygen, sodium, silica, iron, aluminum and phosphate) were monitored by analyzing grab and online samples taken at eight key sampling points.

Findings

Results indicated that pH was the most critical parameter which was not mainly within the recommended ranges of widely used standards and guidelines at all key sampling points that generally increases the occurrence of chemistry-related damages. The other quality parameters were mostly satisfactory.

Originality/value

In this research, the development of a suitable chemical conditioning technique in mixed metallurgy steam and water cycle, fabricated with ferrous and aluminum-based alloys, was studied. The obtained results in this thorough research work was evaluated by comparison with the chemistry limits of the widely used standards and guidelines, and combined use of volatile and solid alkalizing agents was considered as a promising chemical conditioning technique for utilization in mixed metallurgy units of Heller dry cooled CCPPs.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 April 1950

H.W. GREENWOOD

There are three directions in which powder metallurgy has made outstanding contributions to the problems of efficient and economical lubrication. First, we have the porous…

Abstract

There are three directions in which powder metallurgy has made outstanding contributions to the problems of efficient and economical lubrication. First, we have the porous (sometimes called the self‐lubricating) bearing, then there are the steel‐backed bronze lined oil retaining bearings and bushes and the copper lead or other alloy porous bearings and lastly, powder metallurgy has provided materials for filtering oils at high speed and under considerable pressures.

Details

Industrial Lubrication and Tribology, vol. 2 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 13 March 2017

H. Siddhi Jailani, A. Rajadurai, B. Mohan and T. Sornakumar

Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific…

Abstract

Purpose

Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific strength, specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. The purpose of this paper is to describe the tribological studies of Al-Si alloy–fly ash composites manufactured using powder metallurgy technique.

Design/methodology/approach

Al-Si (12 Wt.%) alloy–fly ash composites were developed using powder metallurgy technique. Al-Si alloy powder was used as matrix material, and the fly ash was used as reinforcement. The particle size of Al-Si alloy powder was in the range of 75-300 μm, and the fly ash was in the range of 1-15 μm. The friction and wear characteristics of the composites were studied using a pin-on-disc set up. The test specimen was mated against cast iron disc, and the tests were conducted with the loads of 10, 20 and 30 N, sliding speeds of 0.5, 1 and 1.5 m/s for a sliding distance of 2,000 m.

Findings

The effects of load and sliding speed on tribological properties of the base alloy and Al-Si alloy–fly ash composites pins on sliding with cast iron disc are evaluated. The wear rate of Al-Si alloy–fly ash composites is lower than that of base alloy, and it increases with increasing load and sliding speed. The coefficient of friction of Al-Si alloy–fly ash composites is increased as compared with base alloy.

Practical implications

The development of Al-Si alloy–fly ash composites produced by powder metallurgy technique will modernize the automobile and other industries because near net shape at low cost and good mechanical properties are obtained.

Originality/value

There are few papers available on the development and tribological studies of Al-Si alloy–fly ash composites produced by powder metallurgy technique.

Details

Industrial Lubrication and Tribology, vol. 69 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 February 1987

INTEREST in tin powder for powder metallurgy is growing; not only does it find a place in non‐ferrous powder metallurgy, as in sintered porous bronzes used for bearings…

Abstract

INTEREST in tin powder for powder metallurgy is growing; not only does it find a place in non‐ferrous powder metallurgy, as in sintered porous bronzes used for bearings, but it is valuable as a sintering acid in ferrous powder metallurgy. Work at the Tin Research Institute demonstrates the advantages of small additions of tin powder in iron‐copper‐tin compacts for reducing the sintering temperature and increasing the dimensional stability and wear resistance. Tin powders are beingused worldwide for this purpose and not least in Japan.

Details

Industrial Lubrication and Tribology, vol. 39 no. 2
Type: Research Article
ISSN: 0036-8792

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