Glossary of Contemporary Engineering

141 Pages·1972·20.487 MB·English

by  J. D. Beadle (eds.)

Glossary of
Contemporary Engineering
Glossary of
Contemporary Engineering
Edited by J. D. Beadle
MACMILLAN EDUCATION
ISBN 978-1-349-01263-3 ISBN 978-1-349-01261-9 (eBook)
DOI 10.1007/978-1-349-01261-9
Published by
THE MACMILLAN PRESS LTD
Technical and Industrial Publishing Unit
Brunei Road Basingstoke
Hampshire England
SBN 333 12790 0
© The Macmillan Press Ltd 1972
Reprint of the original edition 1972
Preface
Branches of engineering are growing further apart and, with constant
innovation, development and diversification within each discipline, there
is a strong demand for increased specialisation by the engineer. Along
with this growth, the terminology employed in industry has become
more sophisticated and at times confusing. However, these engineering
disciplines are still linked in practice and those involved in industry are
frequently called upon to understand the precise meaning of the terms
used in a field other than their own.
This glossary is a collection of current terms presented as a straight
forward alphabetical list. It covers a wide range of disciplines, including
mechanical, production and electronic engineering, and is of value both
to students and practising engineers. It includes numerous cross
references and employs the SI system of units. With its wide coverage
and ease of use it should help to bridge the interdisciplinary gap in a
number of situations.
A
A: symbol for ampere; argon; also Absorption current: that fraction of
various physical quantities. current in a dielectric varying pro
Abrasion: abrasive wear; removal of portionally with the rate of accumu
material from a surface by a cutting lation of electric charge within the
or scratching action; resultant effect material.
depends on relative physical Accelerated ageing test: subjects a
characteristics and velocity of the product to intensified but controlled
materials involved; qualitatively conditions of heat, pressure, radia
divided into gouging, grinding, tion or other factors to produce, in
scratching abrasion (qv). a short time, the effects of long
Abrasion: (gears) a form of wear time storage or use under normal
caused by abrasive particles between conditions.
meshing gear teeth, especially when Accelerated test: a test applied to
the normal lubricant film cannot components in which the level of
prevent contact between tooth and applied stress exceeds that stated in
abrasive; depending on size of the reference conditions in order to
particle, wear shows as a polished shorten the time required to observe
or scratched surface on the gear the stress response of the item.
tooth. Accelerating voltage: (electronics,
Abrasive finishing: linishing (qv). oscilloscopes) the cathode-to-viewing
ABS: see acrylonitrile butadiene screen voltage applied to a cathode
styrene. ray tube for the purpose of accelerating
Absolute maximum system: a system the electron beam.
of electrical and thermal ratings for Accelerator: a catalyst, or a substance
components under which the figure added to a catalyst, to accelerate
given for a particular parameter a chemical action, thus reducing the
cannot be exceeded without the time or temperature required for
risk of permanent damage to the processing.
component. Acceptor level: the band of energy in
Absorbent (electrochem): material to an energy level diagram of a semi
immobilise free electrolyte within a conductor crystal lattice to which
cell. have been added acceptor impurities.
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ACCUMULATOR ADDENDUM
Accumulator: (electrochem) common siliceous refractory and using pig
term for rechargeable lead-acid iron low in phosphorus.
(secondary) cells; (data processing) Acid recovery plant: for recovery of
a register in the arithmetic unit of sulphuric acid from acid sludge.
a digital computer in which the Acid refractory: refractory material
results of arithmetic and logical used in furnaces with a high silicon
operations are formed. content (over 90%).
Acetal: thermoplastics material pro Acid sludge (tar): material of high
duced by polymerisation of formal relative density (sp gr) formed
dehyde and possessing high soften during chemical refining of oils by
ing point and numerous good sulphuric acid; can usually be
physical properties resulting in its separated by settling or centrifuging.
use for bearing, gears, bushes, etc. Acoustic surface wave devices: single
Acetal copolymers: thermoplastic crystal semiconductor devices in
materials produced by polymerisa which amplification is achieved by
tion of formaldehyde with other passing a signal along the surface
monomers, as opposed to polyacetal of a semiconductor chip as a
mechanical wave which interacts
(qv).
with the electrical properties of the
Acid cleaning: a process in which a crystal, giving an increase of the
solution of a mineral acid, organic
power transfer.
acid or acid salt in combination with
Acrylic polymers: these are based on
a wetting agent and detergent is
esters of acrylic acid and/or of its
used to remove oxide, oil, grease
homologue, methacrylic acid.
and soil from metal surfaces.
Acrylic resins: thermoplastic material
Acid dew point: (combust) tempera produced by polymerisation of an
ture of deposition of acid solutions,
acrylic resin. Can be extremely clear,
eg sulphur oxides in water, from eg 'Perspex' (polymethylmethacry
flue gas; important factor in design
late).
of eg exhaust systems, chimneys, to
Acrylonitrile: acrylic monomer con
avoid corrosion and production of
taining nitrogen used with styrene,
smut.
styrene and butadiene, or butadiene
Acid dip: a dip solution usually con to produce thermoplastics and
sisting of sulphuric acid, nitric rubbers.
acid, hydrochloric acid, and water, Arcylonitrlle butadiene styrene:
used to give a bright surface to thermoplastic material produced by
brasses; also general term for copolymerisation of acrylonitrile,
cleaning, etching, brightening dips butadiene and styrene. Exceptionally
used for various metals and alloys high impact strength and good
(eg before electroplating). resistance to heat distortion and
Acid lead: copper-containing lead chemicals, suitable for electroplat
allOly used eg in plant involving ing.
sulphuric acid (ASTM B29-55/66). Activator: alternative term for an
Acid pickling: see pickling. 'accelerator' (qv).
Acid process: steelmaking process in Addendum: (mech) of a gearwheel,
which the furnace is lined with a the distance between the pitch
2
ADDITIVE AL
circle (qv) and the outside diameter Ageing: term generally used to indicate
(od) of the wheel; ie the dimension a change in properties of a material
by which the od is greater than the that .occur with time, under normal,
pitch circle; see dedendum. specially controlled or adverse con
Additive: material used to modify ditions; eg deterioration of rubber
or plastics caused by exposure to
properties of a product such as a
atmospheric air or ozone, or to heat
fuel; eg to reduce smoke, improve
or light; also changes in structure or
ignition, depress pour point, reduce
properties of metals and alloys such
wear, corrosion, sludge; odour may
as recrystallisation, age-hardening.
be added to gases to make them
detectable. AGMA: American Gear Manufac
turers Association; issue standards,
Additives (oil): substances added to
specifications, general data.
petroleum fractions to modify their
Air cell (diesel): combustion chamber
natural properties; eg tetraethyl lead
system in which fuel is injected into
to improve gasoline octane num
the main chamber (open to the
ber (anti-knock additive); special
cylinder, as in open chamber design)
materials for production of detergent
which is connected by narrow
oils.
throat(s) to one or more air cells in
Adhesive wear: (mech) damage caused
which rapid secondary combustion
when two surfaces loaded together
takes place; uses high proportion of
are made to slide, thus breaking
air charge; is suitable for automotive
adhesive junctions ('welds') between
uses.
the two surfaces (materials) and
Air cored coils: (electronics) coils with
possibly leading to pick-up or scuff
no magnetic material used in their
ing (transfer of material from one
construction; include coils wound on
surface to the other), creation of
non-magnetic formers as well as
loose particles, and severe wear
air-spaced coils.
(gross surface damage).
Air-hardening steel: alloy steel that can
Admiralty brass: brass of the
be hardened by cooling in air
composition: copper 70%, zinc 29%
instead of in water. Typical com
and tin 1%. The tin is added to
position: carbon 0.3%, nickel 4.0%
increase strength and corrosion
and chromium 1.5%.
resistance.
Air injection: applied in a fuel system
Admiralty gunmetal: copper-tin alloy to force a fuel charge into a com
(ie bronze) with copper 88%, tin bustion, or pre-combustion, space;
10% and zinc 2%. uses highly compressed air.
Mter running: running on. Air register: device that admits air to
Ag: symbol for silver. a fuel burner and controls flow
pattern to promote good burning.
Age-hardening: change in properties
Air-set sand: a wet mix of sand, resin
(eg increase in tensile strength and
and catalyst which is self-curing at
hardness) that occurs in certain
ambient temperature.
metals at ambient temperature after
heat treatment (as in Duralumin) or Air-slip forming: bubble assist vacuum
after cold working (as in mild steel). forming (qv).
Also known as ageing. AI: symbol for aluminium.
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ALKALI ACT ALTERNATIVE FUEL ENGINE
Alkali Act: UK legislation of 1906 to types include austenitic, high chrom
register works (production plants of ium, high silicon, and nickel-contain
various classes), and to control waste ing.
emission from them; extended 1966. Alloy diode: a diode manufactured
Alkaline cleaning: the removal of from a semiconductor wafer to
soiling from a metal surface by one which contact leads are welded.
or more of the following mechan Alloy steel: steel containing, in addition
isms: emulsification, dispersion, film to carbon and manganese, inten
shrinkage and saponification. tionally added alloying elements to
impart particular properties.
Alkaline derusting: the use of aqueous
Alloyed diodes: semiconductor junction
caustic-based solutions, containing
diodes usually fabricated using
various chelating agents, to derust
aluminium as a p-type dopant on an
iron and steel, and employed where
n-type crystal.
base metal attack or hydrogen em
Alloy-treated steels: steels which have
brittlement is unacceptable. Alkaline
had an alloying element added to
derusters are considerably less
purify them, but not to form part of
efficient than acid-based products.
the final composition.
Alkaline etching: used to reduce or
Allyl resin: resin used to produce
eliminate surface scratches, die-lines
thermosetting moulding materials
and other imperfections of alumin
and laminates.
ium surfaces. Particularly important
Alpha cut-off: (electronics, semi
as a treatment before anodising,
conductors) that frequency at the
providing a finely etched surface on
point at which the current gain of a
which to build up the anodised film.
transistor has fallen to 0·7 of its low
Alkyd resins: saturated and un
frequency value.
saturated polyester resins used to
Alpha decay: a radioactive decay
produce polyurethanes and for
mode most often found in elements
laminating and casting. Thermo
with high atomic numbers; the
setting alkyd moulding material has
alpha particle is emitted as a discrete
various moulding advantages over
energy not as continuous energy like
aminos and phenolics. See diallyl
the positive and negative beta
phthalate.
particles.
Allotropes: the two or more solid, Alpha iron: iron with a body-centred
liquid or gaseous forms in which an cube crystal system stable below
element may exist. 910 ·c.
Alloy: a material with metallic proper Alternate mode: (electronics, oscillo
ties, consisting of two or more scopes) a means of displaying output
elements of which at least one is a signals of two or more channels by
metal; the number of principal con switching the channels, in sequence,
stituents is indicated by the terms after each sweep.
binary (2, eg Sn-Pb), ternary (3), Alternative fuel engine: designed to
quaternary (4), etc alloy. operate (i) on oil fuel alone with
Alloy cast irons: wide range of highly compression ignition, or (ii) solely on
alloyed irons employed for their gaseous fuel ignited by a spark; fuel
special resistance to eg corrosion, conversion is possible while the
high or low temperatures, wear; engine is running.
4
ALUMI N/SING ANNEALED TEMPER
Aluminising: cementation (qv) process materials are included in the com
for producing protective coatings position.
by heat treatment which causes pre ampere (A): base SI unit of electric
viously sprayed aluminium to be current; defined as constant current
diffused into the product at about which, if maintained in two straight
·c.
850-900 The results are not as parallel conductors (of infinite length
good as those obtained by calorising and negligible cross-section) placed
(qv). 1 m apart in vacuum, would pro
Aluminium: (Al) metallic element, duce between the conductors a force
atomic number 13, atomic weight of 2x10-7 newton per metre of
·c;
26·97, m.pt 658 important length.
structural/protective metal with wide Amplification factor: (e lec, thermionic
range of alloys; used extensively in valves) the ratio of the change in
engineering, packaging, electrical anode voltage to the change in
(eg as conductor material in place control grid voltage producing that
of copper) industries.
effect.
Aluminium brass: copper-zinc-alumi
Amplitude modulation: (elec) impart
nium alloy (eg 77.5-20.5-2%). ing intelligence to a radio carrier
Aluminium bronze: copper with alu wave by causing the amplitude of
minium as principal alloying element the wave to vary in sympathy with
(eg 3-11 %), with or without addition the amplitude of the modulating
of other elements. waveform.
Amino resin: polymer produced from
Analogue computing: an electronic
reaction of an aldehyde (eg formal computing system in which the
dehyde H.CHO) with a compound
quantities to be computed are
containing more than one amino
represented by the magnitude of
(-NH2) group, eg urea, thiourea, generated voltages.
guanidine, cyanamide, dicyanamide,
Andalusite: a silicate of aluminium
melamine, benzoguanamine. Resins
used in ceramic refractories.
also termed aminoplasts; are strictly
amide-, not amine-based. Anderson bridge: (electronics) a modified
Aminoplast: aminoplastic; see amino form of Maxwell bridge used for
resin. measuring inductance in terms of
Aminoplastics: thermosets produced by capacitance and resistance.
condensation of formaldehyde with Angstrom (A.): An SI unit of length,
aminos, such as melamine and urea. used to define very short wave
Amorphous: Material structure or lengths; equal to 10-10 metres.
microstructure that shows no regular Angular misalignment: (of shafts) see
pattern; non-crystalline. misalignment.
Amorphous carbon: non-crystalline Aniline point: lowest temperature at
form of the element carbon, distinct which equal volumes of petroleum
from the crystalline allotropes fuel and aniline become just
graphite and diamond. Term is miscible; high an.pt indicates high
applied to all industrial carbons in paraffin content (good ignition
which the carbon bonding agent has quality), low an.pt=high aromatic.
been converted to amorphous Annealed temper: temper produced
carbon, whether or not graphite by annealing and usually defined by
5