Table Of ContentMACMILLAN
DICTIONARY
OF
MATERIALS AND
MANUFACTURING
CONTRIBUTORS
Stuart Hampshire, BSc(Tech), PhD, MICeram Philip R S Speare, MA, PhD, CEng, MICE
Ceramics and ceramics processing Materials and processes for the construction
industry
Barry Hull, BEng, MMet, PhD, CEng, MIM
Polymers and polymer processing Kevin Walshe, BSc, PhD, CEng, MIProdE
Manufacturing engineering and systems
Peter Ormiston, BSc, PhD, CEng, MIM
Composite materials
MACMILLAN
DICTIONARY
OF
MATERIALS AND
MANUFACTURING
Editor
Vernon John
M
© The Macmillan Press Ltd, 1990
Softcover reprint of the hardcover 1st edition 1990 978-0-333-45558-6
All rights reserved. No reproduction, copy or
transmission of this publication may be made without
written permission.
No paragraph of this publication may be reproduced,
copied, or transmitted save with written permission or in
accordance with the provisions of the Copyright,
Designs and Patents Act 1988, or under the terms of any
licence permitting limited copying issued by the
Copyright Licensing Agency, 33-4 Alfred Place, London
WC1E7DP.
Any person who does any unauthorised act in relation to
this publication may be liable to criminal prosecution
and civil claims for damages.
First published 1990 by
THE MACMILLAN PRESS LTD
London and Basingstoke
Associated companies in Auckland, Delhi, Dublin,
Gaborone, Hamburg, Harare, Hong Kong,
Johannesburg, Kuala Lumpur, Lagos, Manzini,
Melbourne, Mexico City, Nairobi, New York, Singapore,
Tokyo.
British Library Cataloguing in Publication Data
Macmillan dictionary of materials and
manufacturing
1. Materials
I. Vernon, John
620. 11
ISBN 978-1-349-09917-7 ISBN 978-1-349-09915-3 (eBook)
DOI 10.1007/978-1-349-09915-3
CONTRIBUTORS
Stuart Hampshire, BScTech, PhD, M!Ceram. College, Cardiff, Vernon John served as an
engineer officer in the Royal Air Force and worked
After graduating in Ceramics with Refractories as a foundry and development metallurgist before
Technology from Sheffield University, Stuart joining the staff of The Polytechnic, Regent Street
Hampshire worked at the Dyson Group Research (now The Polytechnic of Central London). He
and Development Laboratories. Subsequently, he was in charge of the Materials Group within the
obtained his doctorate at Newcastle University Department of Mechanical Engineering untill987,
after research into the sintering of nitrogen ceram when he left full-time teaching in order to devote
ics and remained at the Crystallography Labora more time to writing. He is a visiting lecturer at
tory of that university as a post-doctoral Research City University and Kingston Polytechnic and is
Associate until joining the staff of the University actively engaged in curriculum development
of Limerick, Ireland, in 1981. He is currently work with SEFI (European Society for
Professor and Head of the Ceramics Research Engineering Education). He is the author of several
Group of the Materials Research Centre and also materials texts (all published by Macmillan)
Assistant Dean (Research) at Limerick. His cur including Introduction to Engineering Materials
rent research interests are on fabrication, micros and (jointly with Barry Hull) Non-Destructive
tructural development, properties and applica Testing.
tions of engineering ceramics, in particular silicon
nitride and oxide semiconductors. Peter Ormiston, BSc, PhD, CEng, MIM.
Barry Hull, BEng, MMet, PhD, CEng, MIM. Peter Ormiston graduated in Metallurgy from
Birmingham University and obtained his doctor
Barry Hull graduated in Metallurgy from the are from Southampton University. He worked for
University of Liverpool and subsequently ob BNFMRA (now The British Non-Ferrous Metals
tained both his masters degree and doctorate from Technology Centre) and in the Metallury Depart
Sheffield University. He has had wide industrial ment of Imperial College of Science and Technol
experience, working for !nco Alloys Europe and ogy, London. He joined the staff of The Polytech
Chloride Technical before taking up a full-time nic of Central London in 1973 and is currently
academic post in 1980. Since then he has held Senior Lecturer in Engineering Materials in the
several teaching appointments, including posi Department of Mechanical Engineering. His par
tions at The Polytechnic of Central London and ticular interests include composites and materials
Sheffield City Polytechnic. He has recently joined selection.
the staff of the mechanical engineering depart
ment at Bradford University. His main research Philip Speare, MA, PhD, CEng, MICE.
and consultancy interests are abrasive flow ma
chining, ceramics processing, transducer design After graduating from Cambridge University,
and test and inspection methods. He is co-author Philip Speare worked for W.S. Atkins and Part
(with Vernon John) of Non-destructil'e Testing, ners, Consulting Engineers. He joined the staff of
also published by Macmillan. City University in 1972 and is currently Senior
Lecturer in the Civil Engineering Department,
Vernon John, BSc, MSc, CEng, MIM, where he lectures on Materials and Analysis and
MIMM. Design of Structures. His research interests in
clude plates and slabs, reinforced masonry and
After graduating in Metallurgy at University concrete materials.
v
vi
Kevin Walshe, BSc, PhD, CEng. MIProdE.
Kevin Walshe completed an engineering appren
ticeship in automobile and aircraft accessory
manufacture, worked as a process and planning
engineer and was subsequently commissioned in
the Royal Electrical and Mechanical Engineers.
After becoming a chartered engineer he obtained
an honours degree in Monetary Economics at
London University. He has held research and
teaching posts at a number of colleges. including
Brunei University, from where he received his
doctorate in Production Technology, and is cur
rently Principal Lecturer in Manufacturing Sys
tems and Industrial Management at The Polytech
nic of Central London. His main Consultancy and
research interests are computer-aided production
management systems.
A
A. Symbol for ampere, the S.I. unit of electric abradability. The abradability, y, of a material is
current. given by y = A'/J.l, where A' is the ABRASION
FACTOR and J.l is the coefficient of friction.
Al polymer. A proprietary name for polyamide
imides manufactured by Amoco Chemicals and abrasion. The removal of material by a mech
used as composite matrices for service at tem anical rubbing action.
peratures up to 200°C.
abrasion factor. The abrasion factor, A'= V/DL
used as composite matsrtioacncedks where V is the volume of material removed in the
course of sliding a distance D under an applied
AA. Abbreviation for ARITHMETICAL AVERAGE. load L.
ABC classification. A manufacturing or stock abrasive cleaning. See SAND BLASTING and SHOT
control system for the classification of manufac BLASTING.
turing materials into three categories:
A- costly items, few in number, but accounting abrasive finishing. See HONING, LAPPING and
for most of the total financial cost, SUPERFINISHING.
B - medium cost items, about 25% of the total
number in stock/progress, abrasive now machining. A finishing process in
C - cheap items, a large majority of jobs but only which a semisolid medium containing fine abrasive
accounting for a minor part of the total finan particles is forced through a hole. One medium
cial cost. used is methyl polyborosiloxane-Silly Putty.
ablative coatings. Intense heating occurs over a abrasive jet machining. A process for cutting
relatively short time in rocket nozzles and in holes or slots in very hard materials using a high
space vehicles during re-entry and it is necessary pressure air or carbon dioxide jet containing
to dissipate this heat energy rapidly to provide entrained dry abrasive particles.
short term protection. Ablative coatings are plas
tics materials or composites which thermally abrasive machining. This covers all processes
degrade into gaseous products and carbon. The in which material is removed by abrasion and
carbon then sublimes (see SUBLIMATION). The includes GRINDING, HONING and LAPPING.
very high latent heat of sublimation for carbon is
responsible for rapid heat dissipation. Examples abrasives. Very hard substances used for the
of materials used in this way are carbon fibre removal of material by scratching, grinding or
reinforced phenolic resin, quartz-filled phenolic polishing. Abrasive powders and particles may
resin and quartz/carbon composites. be bonded to a paper or cloth backing, for ex
ample, emery paper and cloth, consolidated into a
abnormal steels. Steels that do not behave in the solid shape such as a grinding wheel, or used as a
manner that their composition would lead one to paste or powder within a carrying medium such as
expect. Two mild steels of similar carbon con water, kerosene, etc. Abrasive powders are sized
tent for example may behave differently when and graded to produce a wide range of papers,
case carburized with one, the abnormal steel, not wheels and pastes capable of giving high or low
carburizing uniformly and showing surface soft rates of material removal and coarse or fine pol
spots. ished surface finishes.
1
2 ABS
Many different abrasive materials are used in a.c. arc welding. An arc welding process in which
cluding alumina, boron nitride, silicon carbide the power supply to the arc is a.c. One feature of
(carborundum) and diamond powder. Corundum an a.c. arc is that the arc is extinguished twice in
is a naturally occurring alumina and an impure va each cycle, at the points where current is zero, and
riety of corundum is known as emery. Natural re-ignition is necessary. The stability of an a.c. arc
sandstone was the original material used for grind is improved by the presence of stabilizing addi
stones and is still used to a limited extent. Natural tions in the flux coatings of electrodes and an a.c.
silica sand is used for sand blasting. Other abra arc can be used for flux-shielded welding, particu
sives used include magnesia, chromic oxide and larly for ferrous materials. An arc has the ability to
jeweller's rouge (ferric oxide). disperse oxide films from its negative pole. This
feature is of importance in the welding of metals
ABS. ABS is a thermoplastic terpolymerof acrylo with tenacious oxide films, such as stainless steels
nitrile, butadiene and styrene. The general chemi and aluminium alloys. With an a.c. arc this oxide
cal formula is: dispersion will occur during negative half-cycles.
An a.c. arc is often selected for tungsten arc gas
(-CH -CIH -CH -CIH -C H) shielded welding. It is not used for gas shielded
2 2 6 sn metallic arc welding because metal transfer from
CN (CH2- CH =C H-CH2-)m the electrode is less smooth than with d.c. weld
ing. See also ARC WELDING.
ABS materials have good mechanical properties,
outstanding impact strength and are dimension accelerated curing. A process for the curing of
ally stable over a wide variety of conditions. ABS concrete in which a moist, high temperature is
is available in the form of powder and granules for employed to accelerate the hydration process
injection moulding, extrusion and calendering and to produce a more rapid rate of strength gain.
and as sheet for vacuum forming. It has many See AUTOCLA YING, CURING OF CONCRETE and
applications in consumer products such as refrig STEAM CURING.
erator linings, vacuum cleaner bodies and tele
phones. Other applications include automotive accelerator. A catalyst used to accelerate a chemi
parts, instrument panels and safety helmets. cal reaction and thus reduce the time and/or tem
perature required for the reaction. The term is
absorption. The process in which a substance is used particularly in connection with the speeding
taken up into a system by chemical or physical up of polymer cross-linking reactions, the vulcan
means. It also applies to the attenuation and izing of elastomers and in concrete technology. In
scattering of electromagnetic radiation by a connection with concrete it is an admixture used
material. to induce a more rapid rate of hardening. The most
common accelerator used for this is calcium for
absorption (in brick). Absorption is an impor mate. Calcium chloride was once used exten
tant parameter for brick and is defined as the sively but its use is now restricted to unreinforced
amount of water absorbed by a brick expressed concrete because it renders steel reinforcement
as a percentage of dry weight. It is determined by liable to corrosion. Additional strength gains of
boiling in water for five hours. See also ABSORP up to I 00% at one day can be achieved without
TION RATE and SATURATION COEFFICIENT. any reduction in the final strength. The SETTING
TIME is also reduced by the presence of an accel
absorption rate. The rate at which a brick erator. Accelerators are used to enable form work
absorbs moisture, measured by placing the face in to be removed earlier. Accelerators may also be
water for a specified time. The suction rate, or employed in cold weather concreting to reduce
initial absorption rate, is the amount of water the risk of frost damage. Most of the heat of
absorbed in one minute. hydration is evolved more rapidly, leading to
greater temperature rises in the concrete.
Ac. Chemical symbol for the radioactive element
actinium. acceptable quality level (AQL). A ratio, or per
centage, indicating the extent to which a cus
Act, Ac2, AcJ. See ARREST POINTS. tomer is willing to tolerate defectives from a
supplier. The AQL is, traditionally, around 3%
ACM" See ARREST POINTS. for many applications and processes.
acid steel 3
acceptance sampling. It is customary that com fusible non-hardening gums and are of little
ponents or products entering a factory are as commercial importance.
sessed for quality. Usually this is done by inspec
tion of controlled random samples from a batch; acetal resins. See ACETAL.
the parts being classified as acceptable or defec
tive according to ATIRIBUTES. In a single sam acetal copolymers. Thermoplastics produced
pling system a sample of size n is taken from a by the copolymerization of formaldehyde with
batch of size N and inspected. A level of accep other monomers.
tance is set, for example C defects in a sample of
size n, (see ACCEPTABLE QUALITY LEVEL) SO that acetate. A trade name for cellulose triacetate
if not more than C defects are found the batch is fibres. See CELLULOSE ACETATE.
accepted, but if more than C defects are found the
entire batch is rejected. Double or multiple sam acetone. An organic solvent which attacks most
pling systems may be used instead of a single polymers. For example, cellulose acetate fibres
sampling system. are completely soluble in acetone.
accumulator metal. The lead alloys used to acetovis. An acetylated viscose material. See
make the plates in lead-acid storage batteries. VISCOSE.
These are principally alloys of lead containing
between 5% and I 0% antimony and may contain acetylene. Acetylene is the former name, still
small amounts of other elements, such as tin or used widely, of the easily liquefied, unsaturated
silver. The antimony confers added strength and hydrocarbon gas ethine, C,H,. It has a high calo
improves casting performance. rific value, 53.4 MJ/m \ and-is used mainly as a
fuel for oxy-gas welding and cutting torches.
accuracy. The expression of the degree to which
measured value and true value agree. The differ acicular structure. A structure containing a
ence between these values is the error or devia needle-shaped microconstituent - for example
tion. martensite in steels.
acenaphthylene. A thermoplastic polymerized acid. A compound which, when dissolved in
from acenaphthene monomer, a hydrocarbon water, dissociates to some extent yielding a
extracted from coal tar. These polymers re supply of hydrogen ions in solution. Acids react
semble polystyrene in terms of general proper with alkalis and with many metals to give salts.
ties, but are amber coloured and have a high
softening point (c. 250°C). acid casein. Casein precipitated from skimmed
milk by an acid and used in the manufacture of
acetal (POM). Acetal, also known as polyacetal CASEIN GLUES.
or polyoxymethylene (POM), is a thermoplastic
material based on the polymerization of formal acid cleaning. The removal of oil, grease, oxides
dehyde, HCHO. Acetals are strong, rigid mater or other material from the surface of metals by
ials with excellent dimensional stability and resil cleaning in a solution of an organic or mineral
ience. They have a low coefficient of friction and acid, or an acid salt.
retain their properties at temperatures of up to
120°C. They are produced as moulding powders acid dip. The process of dipping brasses in a nitric
for injection moulding, blow moulding and acid/sulphuric acid mixture to remove surface
extrusion.Their main uses are as a substitute for scale and produce a bright finish.
metals in the manufacture of gears, cams, bearing
bushes, shafts, fans, pump parts and water taps. acid refractory. A refractory material with a high
silica content (over 90%) used in metallurgical
acetaldehyde. A colourless, volatile liquid, furnaces to resist high temperatures and attack by
CH,CHO. Polyvinyl acetate synthesized from acid slags, namely those with high silica and low
impure acetylene may contain acetaldehyde as basic oxide content.
an impurity and its presence can reduce the
degree of polymerization. Phenol-acetaldehyde acid steel. Steel made by an acid process, namely
resins have been produced but these are soluble, in a furnace with an acid refractory lining. The
