ISO 20507:2003

INTERNATIONAL ISO
STANDARD 20507
First edition
2003-12-01
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Vocabulary
Céramiques techniques — Vocabulaire

Reference number
©
ISO 2003
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2003
The reproduction of the terms and definitions contained in this International Standard is permitted in teaching manuals, instruction
booklets, technical publications and journals for strictly educational or implementation purposes. The conditions for such reproduction are:
that no modifications are made to the terms and definitions; that such reproduction is not permitted for dictionaries or similar publications
offered for sale; and that this International Standard is referenced as the source document.
With the sole exceptions noted above, no other part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2003 — All rights reserved

Contents Page
Foreword. iv
1 Scope. 1
2 Terms and definitions. 1
2.1 General terms. 1
2.2 Terms for form and processing. 8
2.3 Terms for properties and testing. 15
3 Abbreviations. 19
3.1 Abbreviations for ceramic materials. 19
3.2 Abbreviations for processes. 24
Bibliography . 28
Index . 30

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 20507 was prepared by Technical Committee ISO/TC 206, Fine ceramics.

iv © ISO 2003 — All rights reserved

INTERNATIONAL STANDARD ISO 20507:2003(E)

Fine ceramics (advanced ceramics, advanced technical
ceramics) — Vocabulary
1 Scope
This International Standard provides a list of terms and associated definitions which are typically used for fine
ceramic (advanced ceramic, advanced technical ceramic) materials, products, applications, properties and
processes. The document contains, in separate lists, those abbreviations which have found general
acceptance in the scientific and technical literature; they are given together with the corresponding terms and
definitions or descriptions.
In this International Standard, the terms are defined using the words “fine ceramic”. The definitions apply
equally to “advanced ceramics” and “advanced technical ceramics”, which are considered to be equivalent.
This International Standard does not include terms which, though used in the field of fine ceramics, are of a
more general nature and are also well known in other fields of technology.
[1] [2]
NOTE Terms and definitions of a more general nature are available in ASTM C 1145 , CEN/WI 89 and
[3]
JIS R 1600:1998 . A list of some ISO Standards and Draft ISO Standards of ISO/TC 206 “Fine ceramics” containing
terms defined in this ISO Standard is given in the Bibliography.
2 Terms and definitions
2.1 General terms
2.1.1
advanced ceramic
advanced technical ceramic
fine ceramic
highly engineered, high performance, predominately non-metallic, inorganic, ceramic material having specific
functional attributes
NOTE The use of fine ceramics, advanced ceramics and advanced technical ceramics is interchangeably accepted
in business, trade, scientific literature and ISO Standards.
2.1.2
bioceramic
fine ceramic employed in or used as a medical device which is intended to interact with biological systems
NOTE 1 Bioceramics typically comprise products to repair or replace bone, teeth and hard tissue or to support soft
tissue and/or control its function.
NOTE 2 Implants require a degree of biocompatibility.
NOTE 3 Bioceramics that are intended to interact actively with biological systems are often based on crystalline
hydroxy(l)apatite; also partially crystallized glass or glass-bonded ceramic is used.
2.1.3
carbon-carbon composite
fine ceramic composed of a carbon matrix containing carbon fibre reinforcement
NOTE A carbon-carbon composite can be used as furnace parts or heat resistant tiles for a space shuttle.
2.1.4
ceramic, adj
pertaining to the essential characteristics of a ceramic and to the material, product manufacturing process or
technology
2.1.5
ceramic, noun
inorganic, essentially non-metallic, substantially crystalline product manufactured under the influence of
elevated temperatures
NOTE The concept “ceramic” comprises products based on clay as raw material and also materials which are
typically based on oxides, nitrides, carbides, silicides, borides.
2.1.6
ceramic capacitor
capacitor in which the dielectric material is a ceramic
NOTE e.g., BL (Boundary Layer) capacitor; multi-layer ceramic capacitor.
2.1.7
ceramic catalyst carrier
nonreactive substrate to support a catalyst
NOTE A ceramic catalyst carrier is typically made with a thin wall, has a large surface area and is used in contact
with fluid matter.
2.1.8
ceramic coating
layer of oxide ceramic and/or non-oxide ceramic adhering to a substrate
NOTE 1 Ceramic coatings are produced by a variety of processes, e.g. dipping, plasma spraying, sol-gel coating
process, physical vapour deposition or chemical vapour deposition coating process.
NOTE 2 Ceramic coatings are usually subdivided into thin ceramic coatings (< 10 µm) and thick coatings (W 10 µm).
2.1.9
ceramic cutting tool
tool for machining operations, consisting of a fine ceramic having excellent wear, damage and heat resistance
NOTE Machining includes operations such as turning, drilling and milling.
2.1.10
ceramic filters
2.1.10.1
electrical
filter using a piezoelectric ceramic as a resonator
2.1.10.2
porous
porous ceramic matter to be used in filtering gas or liquid
2.1.11
ceramic for electrical applications
electrical ceramic (deprecated)
electroceramic used in electro-technical applications because of its intrinsic properties
NOTE 1 These intrinsic properties include electrical insulation, mechanical strength and corrosion resistance.
2 © ISO 2003 — All rights reserved

NOTE 2 This term includes ceramics for passive electrical applications, i.e. ceramics with no active electrical behaviour,
having a high electrical resistivity, used for electrical insulation functions.
NOTE 3 This term may apply to silicate ceramics such as steatite and electrical porcelain.
2.1.12
ceramic for electronic applications
electronic ceramic (deprecated)
fine ceramic used in electrical and electronic engineering because of intrinsic, electrically related properties
2.1.13
ceramic for nuclear applications
nuclear ceramic (deprecated)
fine ceramic having specific material properties required for use in the generation of nuclear energy
NOTE Ceramics for nuclear applications include materials for nuclear fuels, neutron absorbers, burnable neutron
poisons, diffusion barrier coatings and inert container elements.
2.1.14
ceramic for optical applications
optical ceramic
fine ceramic used in optical applications because of its intrinsic properties
NOTE 1 e.g., transparent alumina is used for high pressure sodium lamp envelopes.
NOTE 2 Optical ceramics are tailored to typically exploit transmission, reflection, absorption of visible and near-visible
electromagnetic radiation.
2.1.15
ceramic heating resistor
heater making use of an electric conductive or a semiconductive property of ceramics
2.1.16
ceramic honeycomb
fine ceramic having many holes with a typically honeycomb shape
NOTE A ceramic honeycomb is typically used as a ceramic catalyst carrier, a filter or a heat exchanger regenerator,
and is typically made of cordierite, mullite or aluminium titanate.
2.1.17
ceramic ionic conductor
electroceramic in which ions are transported by an electric potential or chemical gradient
2.1.18
ceramic matrix composite
CMC
fine ceramic composed of a ceramic matrix containing reinforcement
NOTE The reinforcement is often continuous, i.e. ceramic filaments, distributed in one or more spatial directions, but
this term is also used for discontinuous reinforcement, e.g short ceramic fibres, ceramic whiskers, ceramic platelets or
ceramic particles.
2.1.19
ceramic optical waveguide
optical waveguide formed on the surface of a ceramic substrate
NOTE Optical single crystal of LiNbO is typically used as a ceramic substrate.
2.1.20
ceramic sensor
sensor making use of semiconductive, magnetic or dielectric properties of a fine ceramic
2.1.21
ceramic substrate
ceramic body, sheet or layer of material on which some other active or useful material or component may be
deposited or laid
NOTE e.g., an electronic circuit laid on an alumina ceramic sheet. In catalysis, the formed, porous, high surface-area
carrier on which the catalytic agent is widely and thinly distributed for reasons of performance and economy.
2.1.22
ceramic varistor
ceramic material having high electrical resistivity at low voltage but high electrical conductivity at high voltage
NOTE A zinc oxide varistor can be used as a protector in an electronic circuit.
2.1.23
cermet
composite material consisting of at least one distinct metallic and one distinct ceramic phase, the latter
normally being present at a volume fraction greater than 50 %
NOTE 1 The ceramic phase, typically, has high hardness, high thermal strength, good corrosion resistance and the
metallic phase has good toughness and elastoplastic behaviour.
NOTE 2 The term “cermet” is a contracted form of ceramic metal.
NOTE 3 Materials containing typically less than 50 % by volume of ceramic phase are commonly called “metal matrix
composites”.
2.1.24
coated ceramic
ceramic coated by a layer or multi-layers of organic or inorganic material
2.1.25
continuous fibre ceramic composite
CFCC
ceramic matrix composite in which the reinforcing phase(s) consist(s) of continuous filaments, fibres, yarn or
knitted or woven fabrics
2.1.26
diamond-like carbon
form of carbon made by a CVD process, having hardness much higher than ordinary carbon but lower than
diamond
NOTE Diamond-like carbon is typically used as a hard coat material for cutting tools or memory disks.
2.1.27
dielectric ceramic
ceramic dielectric
electroceramic having controlled dielectric properties
2.1.28
discontinuous fibre-reinforced ceramic composite
ceramic matrix composite material reinforced by chopped fibres
2.1.29
far-infrared radiative ceramic
fine ceramic with specific property to radiate in the far-infrared
4 © ISO 2003 — All rights reserved

NOTE Far-infrared radiative ceramics are typically used as heaters for industrial and domestic applications.
2.1.30
ferrite
fine ceramic with ferrimagnetic behaviour, having ferric oxide as a major constituent
NOTE Magnetic ceramic is used as a synonym of ferrite, but encompasses non-oxide containing materials as well.
2.1.31
ferroelectric ceramic
non-linear polarizable electroceramic, generally with a high level of permittivity, exhibiting hysteresis in the
variation of the dielectric polarization as a function of the electric field strength and in the temperature
dependence of the permittivity
NOTE Polarization results in electrostrictive, piezoelectric, pyroelectric and/or electro-optic properties, which
disappear above the transition or Curie temperature.
2.1.32
functional ceramic
fine ceramic, the intrinsic properties of which are employed to provide an active function
NOTE e.g., electronic or ionic conductor, component with magnetic, chemical or mechanical sensing function.
2.1.33
functionally graded ceramic
fine ceramic, the properties of which are deliberately varied from one region to another through spatial control
of composition and/or microstructure
2.1.34
glass-ceramic
fine ceramic derived from bulk glass or glass powder by controlled devitrification
NOTE The glass is thermally treated to induce a substantial amount of crystallinity on a fine scale.
2.1.35
hard ferrite
ferrite having strong magnetic anisotropy and high coercivity
NOTE e.g., barium hexaferrite, used as permanent magnets in loudspeakers; strontium hexaferrite, used as
permanent magnet segments in electric motors.
2.1.36
high-temperature superconductor
HTS
HTSC
superconducting ceramic having superconducting properties at temperatures above 77 K, the boiling point of
liquid nitrogen
NOTE Superconducting ceramics typically comprise certain combinations of oxides of copper, rare earths, barium,
strontium, calcium, thallium and/or mercury.
2.1.37
in-plane reinforced (2D) ceramic matrix composite
ceramic matrix composite with continuous reinforcement, which is distributed principally in two directions
NOTE The reinforcement comprises typically ceramic filaments.
2.1.38
machinable ceramic
ceramic that, after the last consolidation heat treatment, can be machined to tight tolerances using
conventional hardmetal or abrasive tools
NOTE 1 e.g., boron nitride, glass-ceramics and porous aluminas.
NOTE 2 The natural mineral talc and pyrophyllite, machined and heat-treated, are sometimes also referred to as a
machinable ceramics.
2.1.39
metallized ceramic
fine ceramic product with a coherent, predominantly metal layer applied to its surface
NOTE 1 Processes for metallization include painting, printing, electrolytic deposition and physical vapour deposition.
NOTE 2 Metallization is carried out for specific modification of surface properties or to produce an interlayer for
promoting the formation of a high integrity bond with another material (often metallic).
2.1.40
monolithic ceramic
fine ceramic which has undergone consolidation through sintering to obtain a microstructure consisting
predominantly of ceramic grains of one or more phases which are homogeneously distributed on a scale
which is small compared to the dimensions of the part
NOTE 1 Ceramic parts with low or moderate porosity are included, whereas ceramic matrix composites with ceramic
filaments are excluded.
NOTE 2 A secondary phase can also be non-ceramic.
2.1.41
multidirectional ceramic matrix composite
ceramic matrix composite with continuous reinforcement which is spatially distributed in at least three
directions
NOTE The reinforcement typically comprises ceramic filaments.
2.1.42
nanocomposite ceramic
composite with highly designed microstructure in which fine particles of nanometers in size are dispersed in a
ceramic matrix
SEE particulate reinforced ceramic matrix composite (2.1.46).
2.1.43
non-oxide ceramic
fine ceramic produced primarily from substantially pure metallic carbides, nitrides, borides or silicides or from
mixtures and/or solid solutions thereof
2.1.44
opto-electronic ceramic
electroceramic, typically a ferroelectric ceramic in which the optical properties are controlled by electrical
means
2.1.45
oxide ceramic
fine ceramic produced primarily from substantially pure, metallic oxides or from mixtures and/or solid solutions
thereof
NOTE This term may also be applied to ceramics other than fine ceramics.
2.1.46
particulate reinforced ceramic matrix composite
ceramic matrix composite in which the reinforcing components are particles of equiaxed or platelet geometry
(in contrast to whiskers or short fibres)
SEE nanocomposite ceramic (2.1.42)
6 © ISO 2003 — All rights reserved

2.1.47
piezoelectric ceramic
piezoceramic
electroceramic, typically a ferroelectric ceramic, in which the elastic and dielectric properties are coupled, with
practically linear dependence, between the magnitude and direction of mechanical force applied and the
electric charge created, or conversely, between the strength and direction of an electric driving field and the
elastic deformation obtained
NOTE 1 Typical piezoelectrics are barium titanate and lead zirconium titanate.
NOTE 2 Elastic deformation under the influence of an electric driving field is termed the inverse piezoelectric effect.
NOTE 3 Piezoelectric ceramics are capable of transforming mechanical energy into electrical energy or signals and
vice versa.
2.1.48
silicate ceramic
ceramic, made mainly from minerals and/or other siliceous raw materials, resulting in a microstructure with a
substantial amount of silicate phases
NOTE Electrical porcelain and steatite ceramic are typical silicate ceramics.
2.1.49
soft ferrite
ferrite having a weak magnetic anisotropy, resulting in high magnetic permeability and low magnetic loss
NOTE e.g., manganese-zinc-ferro-ferrite with spinel type crystal structure, used for coils, transformers for energy
conversion; ferrite with garnet-type crystal structure, such as yttrium iron garnet, used for microwave applications.
2.1.50
structural ceramic
fine ceramic employed primarily in structural applications for its mechanical or thermomechanical performance
NOTE The term “structural ceramic” is also applied to clay products for constructional purposes.
2.1.51
superconducting ceramic
electroceramic showing practically zero electrical resistance below a certain temperature
NOTE Superconducting ceramics typically comprise certain combinations of oxides of copper, rare earths, barium,
strontium, calcium, thallium and/or mercury and most of them are high-temperature superconductors.
2.1.52
surface-modified ceramic
fine ceramic in which the surface has been subjected to a deliberate physical or compositional modification
NOTE 1 Surface modification is normally intended to enhance properties or performance.
NOTE 2 Modification processes include ion diffusion, ion exchange and chemical reactions such as oxidation.
2.1.53
thick ceramic coating
ceramic coating of a thickness typically equal to or greater than 10 µm
NOTE Thick ceramic coatings are produced typically by thick film technology such as dipping (slurry), screen printing
or plasma spraying and so on.
2.1.54
thin ceramic coating
ceramic coating of a thickness typically less than 10 µm
NOTE Thin ceramic coatings are produced typically by thin film technology such as sol-gel coating process (dipping,
spin coating), physical vapour deposition coating process.
2.1.55
unidirectional (1D) ceramic matrix composite
ceramic matrix composite with continuous reinforcement which is distributed in one single direction
NOTE The reinforcement typically comprises ceramic filaments.
2.2 Terms for form and processing
2.2.1
as-fired surface
external surface of a ceramic product after sintering
NOTE The as-fired surface may be relatively rough compared with surfaces machined after sintering and may have
e.g. pits and adherent debris.
2.2.2
binder
one or more mainly organic compounds which are added to the ceramic body in order to enhance compaction
and/or to provide enough strength to the green body to permit handling, green machining, or other operations
prior to sintering
2.2.3
binder phase
tough matrix phase embedding a rigid, hard, main, ceramic phase in a composite material
NOTE 1 e.g., binder phase: cobalt, nickel; hard phase: tungsten carbide, tantalum carbide.
NOTE 2 A tough matrix phase reduces the brittleness and crack sensitivity and improves the strength and toughness of
the composite material.
2.2.4
calcining
calcination
process for changing the chemical composition and/or phases of a powder or powder compact by the action of
heat and atmosphere, prior to consolidation and processing
NOTE This process is typically used for the removal of organic material, combined water and/or volatile material from
a powder or powder compact.
2.2.5
casting
drain (hollow) casting
forming ceramic ware by introducing a body slip into an open, porous mould, and then draining off the
remaining slip when the cast piece has reached the desired thickness
2.2.6
ceramic agglomerate
accretion of ceramic particles forming a coherent, but weakly bonded mass
NOTE Ceramic agglomerates are unintentionally generated during manufacture and preparation of ceramic powders
for ceramic production and may be difficult to break down.
2.2.7
ceramic aggregate
accretion of ceramic particles forming a coherent mass with strong interfacial bonding
8 © ISO 2003 — All rights reserved

NOTE Ceramic aggregates are intentionally generated during manufacture and preparation of ceramic powders and
are difficult to break down.
2.2.8
ceramic body
totality of all inorganic and organic raw material constituents after preparation of ceramic powder but before
the shaping and heat treatment to produce a ceramic
2.2.9
ceramic fibre
unit of ceramic matter of relatively short length, characterized by a high length to diameter ratio
NOTE 1 Ceramic fibres may consist of oxide or non-oxide material.
NOTE 2 Ceramic fibres are used as reinforcement in ceramic matrix composites in which case the diameter is usually
smaller than 20 µm, the aspect ratio typically being greater than 100.
2.2.10
ceramic filament
unit of ceramic matter of small diameter and very long length, considered to be continuous
NOTE 1 Ceramic filaments may consist of oxide or non-oxide material.
NOTE 2 Ceramic filaments are typically used as reinforcement in ceramic matrix composites, as separate filaments, as
tow and as woven or non-woven fabrics.
2.2.11
ceramic grain
individual crystal within the polycrystalline microstructure of a ceramic
NOTE This term is also used for individual, usually hard, particles of abrasive or refractory materials.
2.2.12
ceramic granulate
mass of granules produced from a ceramic body, usually in a free flowing form, used as a feed stock for
producing a green body
NOTE There are many granulation processes; the size of the granules is typically 40 µm or greater.
2.2.13
ceramic particle
small quantity of ceramic matter, monocrystalline, polycrystalline or amorphous, in a discrete mass of size and
shape controlled by its fabrication process
NOTE Individual particles may accrete into unintentional ceramic agglomerates or intentional ceramic aggregates, or
may be processed to form a ceramic granulate.
2.2.14
ceramic platelet
unit of ceramic matter, typically consisting of a single crystal in a plate-like shape
NOTE 1 Ceramic platelets may consist of oxide or non-oxide material.
NOTE 2 Ceramic platelets are used as reinforcement in ceramic matrix composites in which case the width of the
platelets is usually smaller than 50 µm.
2.2.15
ceramic (powder) preparation
preparation of ceramic powder
process of converting powders and additives into a ceramic body, usually by comminution and/or mixing of the
powder with binders and lubricants to provide the required chemical and physical characteristics
2.2.16
ceramic precursor
chemical or mixture of chemicals employed for the manufacture of a ceramic powder, ceramic granulate, thin
ceramic coating, monolithic ceramic or a ceramic matrix composite, or ceramic fibres, ceramic whiskers or
ceramic platelets, differing in composition from the fabricated ceramic product
NOTE 1 e.g., gaseous silicon tetrachloride used for the formation of silicon nitride; metal alkoxides used for the
formation of metal oxide powders.
NOTE 2 This term is usually applied to gas or liquid mixtures which are decomposed to form ceramic materials.
2.2.17
ceramic whisker
unit of ceramic matter, consisting typically of a single crystal having a needle-like shape
NOTE 1 Ceramic whiskers may consist of oxide or non-oxide material.
NOTE 2 Ceramic whiskers may be used as reinforcement in ceramic matrix composites in which case the diameter of
the crystals is usually smaller than 3 µm, the aspect ratio being less than 100.
2.2.18
chemical vapour deposition
CVD
process for producing a fine ceramic by reacting gaseous species and condensing the reaction product or by
heterogeneous reaction at the surface of a substrate
NOTE This process may be used for the preparation of a solid ceramic or a ceramic powder or a coated ceramic or
for infiltration of a heated substrate.
2.2.19
chemical vapour deposition coating process
CVD coating process
chemical vapour deposition used for the formation of a fine ceramic coating on a substrate
2.2.20
chemical vapour infiltration
CVI
chemical vapour deposition used for producing a fine ceramic by heterogeneous reaction at the pore surface
of a heated porous ceramic preform
NOTE CVI is typically used to produce ceramic filament reinforced ceramic matrix composites.
2.2.21
cold isostatic pressing
CIP
process of preparing a green body from a ceramic powder or a ceramic granulate by the use of (pseudo-)
isostatic pressure at or near room temperature
NOTE This process is sometimes called “CIPing”.
2.2.22
consolidation
process of rigidizing a ceramic body
10 © ISO 2003 — All rights reserved

NOTE Consolidation methods include mechanical densification, chemical bonding and sintering.
2.2.23
doctor blade process
process to form a ceramic sheet in which ceramic powder, binder and solvent are mixed and spread by a knife
edge (or a doctor blade) on to a carrier film
NOTE The doctor blade process is used to form a ceramic sheet with good dimensional accuracy by adjusting the
distance between a knife edge (or a doctor blade) and a carrier film.
2.2.24
extrude, verb
to shape a plastic body by forcing material through a die
2.2.25
filler
organic (or rarely inorganic) additive to a ceramic body which burns out or decomposes during firing and
creates intentional porosity
NOTE e.g., discrete polymer particles added to a ceramic body with the intention of forming discrete pores.
2.2.26
fillers
2.2.26.1
particulate
predominantly inert, usually particulate substance, introduced into a fine ceramic body to control processing or
properties
NOTE e.g., particles of silicon carbide used as a filler in a silicon-based polymer precursor for dimensional control in
subsequent consolidation.
2.2.26.2
particulate ceramic
predominantly inert, usually particulate ceramic substance typically introduced into a polymer or metallic body
to modify properties
NOTE e.g., aluminium oxide or aluminium hydroxide introduced into a polymer to enhance its stiffness and wear
resistance.
2.2.27
gas pressure sintering
GPS
sintering by the combined application of heat and gas pressure
NOTE 1 e.g., gas pressure sintered silicon nitride, GPSSN.
NOTE 2 The gas pressure is typically not greater than 10 MPa.
2.2.28
green body
green part
ceramic body that is compacted and/or shaped, but not yet heat-treated
2.2.29
green machining
machining of a green body to a predetermined shape
2.2.30
hot isostatic pressing
HIP
process of making a fine ceramic by application of an isostatic gas pressure at elevated temperatures
NOTE 1 The object may be an encapsulated powder or green body, or a pre-densified fine ceramic. Gas pressures are
typically much greater than 10 MPa.
NOTE 2 This process is sometimes called “HIPing”.
2.2.31
(uniaxial) hot pressing
HP
process of making a fine ceramic, normally by application of a unidirectional (uniaxial) force at elevated
temperature
NOTE For uniaxial hot pressing, an inductively heated graphite die is usually employed.
2.2.32
injection moulding
IM
process of shaping a green body by injecting an appropriately formulated mass into a mould or die
2.2.33
liquid-phase sintering
LPS
sintering achieved by the presence of a liquid phase
NOTE The amount and properties of the liquid phase are determined by the composition of the green body,
temperature and pressure. This process is enhanced by accelerated diffusion and dissolution-precipitation phenomena.
2.2.34
low-pressure chemical vapour deposition
LPCVD
chemical vapour deposition at low gas pressure
NOTE The gas pressure is typically less than 0,01 MPa.
2.2.35
machined and refired
state of treatment of a fine ceramic component that has been machined and subsequently refired to modify
the surface properties
2.2.36
manufacture of ceramic powders by flame pyrolysis
process of formation of ceramic particles by passing reactants through the combustion zone of a flame
2.2.37
manufacture of ceramic powders by gas-phase reaction
process of formation of ceramic particles from gaseous reactants using an external stimulus
NOTE 1 e.g., silicon nitride powder produced by reaction between silicon tetrachloride gas and ammonia gas.
NOTE 2 External stimuli include heating, electrical discharge and laser irradiation.
2.2.38
manufacture of ceramic powders by sol-gel technique
process of formation of ceramic particles by using sol-gel processing in which the sol is dispersed into fine
droplets before conversion into a gel, followed by further processing
SEE sol-gel processing (2.2.54)
12 © ISO 2003 — All rights reserved

NOTE 1 The conversion of sol into gel can be by a reaction such as dehydration. The common route is a hydrolysis
reaction followed by condensation to give direct precipitation of fine ceramic particles.
NOTE 2 Further processing includes drying and calcining of gel.
2.2.39
metal-organic chemical vapour deposition
MOCVD
chemical vapour deposition using single or mixed metal-organic vapours
2.2.40
microwave sintering
use of high power, high frequency electromagnetic waves (microwaves) to heat a green body by internal
dielectric loss to a sufficient temperature for sintering
NOTE The action of the microwaves may in some cases accelerate the sintering process.
2.2.41
plasma-enhanced chemical vapour deposition
PECVD
chemical vapour deposition using a plasma
NOTE The reaction in the gaseous phase can, e.g., be stimulated by application of a plasma formed by coupled laser.
2.2.42
physical vapour deposition
PVD
process for producing, e.g., a ceramic film by transport of the required chemical species, some or all of which
are generated from a source or sources by physical means such as thermal, electron beam, arc or laser
evaporation or sputtering, and deposition on to a prepared substrate with or without the assistance of a
reactive atmosphere, ionic bombardment or a gas plasma
2.2.43
polycrystalline diamond
PCD
polycrystalline form of carbon with cubic crystalline structure
NOTE 1 Polycrystalline diamond is normally prepared by high-pressure and high-temperature processing to achieve
direct bonding between diamond grains.
NOTE 2 Polycrystalline diamond film is normally prepared by low-pressure chemical vapour deposition.
2.2.44
post-sintering
PS
sintering after a previous consolidation stage
NOTE e.g., post-sintered reaction-bonded silicon nitride, PSRBSN.
2.2.45
pressureless sintering
PLS
sintering in the absence of a raised mechanical or gas pressure
NOTE e.g., pressureless-sintered silicon nitride, PLSSN.
2.2.46
pyrolytic carbon
form of carbon produced through the thermal decomposition of carbon-containing precursors
NOTE Precursors are, e.g., long-chain polymers or reacting gaseous mixtures.
2.2.47
pyrolytic graphite
form of high-purity graphite produced from the vapour phase by thermal decomposition of carbon-containing
gas and deposition on to a substrate
NOTE Pyrolytic graphite usually has a highly oriented microstructure and strongly anisotropic properties.
2.2.48
reaction bonding
RB
process for producing a fine ceramic by consolidation of a green body by a chemical reaction between
gaseous, liquid or solid species at elevated temperature producing a bond between ceramic particles
NOTE 1 e.g., silicon nitride objects can be produced by the reaction of silicon with nitrogen; reaction-bonded silicon
nitride, RBSN.
NOTE 2 The use of this term for a process that falls under the definition of reaction sintering is deprecated.
2.2.49
reaction sintering
RS
process for producing a fine ceramic by consolidation of a green body by a solid state chemical reaction
accompanied by solid state sintering at high temperatures to produce a bond between ceramic particles
NOTE 1 e.g., during the production of aluminium titanate ceramics, aluminium titanate can be formed by a solid state
reaction between aluminium oxide and titanium oxide.
NOTE 2 The use of this term for liquid or gaseous reaction bonding process is deprecated.
2.2.50
reinforcement
ceramic particles, ceramic whiskers, ceramic platelets, ceramic fibres or ceramic filaments incorporated in a
fine ceramic, normally for the purpose of modifying mechanical properties
NOTE 1 The reinforcement may alternatively be non-ceramic.
NOTE 2 The mechanical properties may be modified as regards their strength, toughness, wear resistance, hardness,
creep resistance or other characteristics.
NOTE 3 For ceramic matrix composites, continuous reinforcement, i.e. ceramic filaments, is often used.
2.2.51
roll compaction
process of shaping a green body by feeding a granulated ceramic body between contra-rotating rollers which
compact it into a strip or sheet
2.2.52
self-sustained high temperature synthesis
SHS
process for producing a solid fine ceramic in which primarily the heat of the exothermic reaction from
reactant(s) is utilized
2.2.53
sintering
process of densification and consolidation of a green body by the application of heat with resulting joining of
ceramic particles and increasing contact interfaces due to atom movement within and between the ceramic
grains of the developing polycrystalline microstructure
14 © ISO 2003 — All rights reserved

NOTE Sintering may take place either directly or through the agency of a secondary phase, e.g., in reaction sintering
and liquid-phase sintering.
2.2.54
sol-gel processing
chemical synthesis of ceramic materials typically based on hydrolysis of ceramic precursors (alkoxides, acids,
hydroxides) and subsequent condensation or aggregation to form sols followed by conversion to a gel and
further processing
NOTE 1 A sol is a liquid dispersion of colloidal solid particles of up to several hundred nanometers in size, while a gel
is a rigid interconnected network filled with either gas or liquid.
NOTE 2 Further processing includes, e.g., drying, calcining and sintering.
NOTE 3 Organically-modified inorganic networks (ormocers) can be formed by sol-gel processing.
2.2.55
sol-gel coating process
process for producing a fine ceramic coating on a product by initially covering the surface with ceramic
precursor followed by sol-gel processing
2.2.56
sol-gel consolidation technique
processing technique to produce a fine ceramic by using sol-gel processing in combination with casting,
extrusion or impregnation with subsequent drying and sintering
NOTE The size of articles produced by this technique is often limited by the large shrinkage arising from such
processes.
2.2.57
spark plasma sintering
sintering process in which a compact of powder is heated by an electric discharge
2.2.58
tape casting
process of shaping a green body in the form of a tape by casting a slurry of ceramic body (slip) as a film on a
flat surface, followed by drying
NOTE Organic additions to the slip give the tape flexibility and permit forms to be made from it by cutting, stamping
or punching, from which components such as substrates, packages and capacitors can be manufactured.
2.2.59
vitreous carbon
form of carbon derived through solid phase carbonization from a preform comprising an appropriate highly
cross-linked polymer
NOTE Vitreous carbon is characterized by a pseudo-amorphous, isotropic structure with low density and non-
permeability for gases.
2.3 Terms for properties and testing
2.3.1
bulk density of ceramics
value obtained by dividing the mass of test specimen by the external volume of ceramic specimen
2.3.2
chip
piece of material broken off the edge or corner of a ceramic test-piece or component
NOTE When pieces of material break off the edges or corners of a test-piece or component they leave a “chipped
area”.
2.3.3
competing failure modes
distinguishably different types of fracture initiation processes in ceramic test-pieces or components that result
from concurrent critical flaw distributions
2.3.4
compound critical flaw distribution
flaw distribution in ceramic test-pieces or components which contain more than one type of strength-
controlling flaw not occurring in a purely concurrent manner
NOTE All test-pieces contain flaw type A and some additionally contain a second independent type B.
2.3.5
compressive stress
maximum value of uniaxial compressive stress at the instant of collapse of a ceramic test-piece, either by
shearing or fragmentation
2.3.6
concurrent critical flaw distribution
competing critical flaw distribution
type of flaw distribution where every ceramic test-piece or component contains representative defects of each
independent flaw type which compete with each other to cause failure
2.3.7
crack
plane of fracture in a ceramic test-piece or component without complete separation
2.3.8
critical flaw
flaw acting as the source of a failure in a ceramic test-piece or component
2.3.9
critical flaw distribution
distribution of type, shape and size of critical flaws in a population of ceramic test-pieces or components
2.3.10
dynamic fatigue
diminution of mean strength by the process of subcritical crack growth (or slow crack growth) of a batch of
ceramic test-pieces or components when subjected to reduced levels of constant stressing rate
NOTE This term is normally applied when elastic behaviour is prevalent.
2.3.11
exclusive critical flaw distribution
type of flaw distribution created by mixing and randomizing test-pieces or components from two or more
versions or batches of ceramic material where each version contains a single strength-controlling flaw
population
NOTE Each test-piece or component contains defects exclusively from a single distribution, but the total data set
reflects more than one type of strength-controlling flaw.
2.3.12
extraneous flaw
type of flaw observed in the fracture of ceramic test-pieces manufactured for the purpose of a test programme,
but which will not appear in manufactured components or vice versa
NOTE e.g. test-pieces may have flaws from machining, which do not occur in the manufactured components.
16 © ISO 2003 — All rights reserved

2.3.13
flaw
inhomogeneity, discontinuity or other structural irregularity in ceramic material
NOTE 1 e.g., grain boundary, large grain, pore, impurity, crack.
NOTE 2 The term “flaw” should not be taken to mean that the material is functionally defective, but rather as an
inevitable microstructural inhomogeneity.
NOTE 3 When the material is mechanically loaded, a flaw provides a stress concentration and enhances the risk of
mechanical failure.
2.3.14
flaw distribution
spread of type, shape and size of flaws within a single ceramic test-piece or component
2.3.15
flexural strength
maximum stress supported by a specified beam in bending at the instance of failure as determined at a given
stress rate in a particular environment.
2.3.16
four-point flexural strength
four-point bending strength
strength determined by bending a beam-shaped ceramic test-piece whereby the test-piece is supported on
bearings near its ends, and is loaded equally at two positions symmetrically disposed about the centre of the
supported span
NOTE The term “quarter-point flexural strength” is sometimes used for the strength as measured by the four-point
flexure geometry wherein the load positions are each one-quarter of the support span from the support bear
...