EN 60672-1:1995

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ceramic and glass insulating materials - Part 1: Definitions and classification (IEC 60672-1:1995)Keramik- und Glas-Isolierstoffe -- Teil 1: Begriffe und GruppeneinteilungMatériaux isolants à base de céramique ou de verre -- Partie 1: Définitions et classificationCeramic and glass insulating materials -- Part 1: Definitions and classification29.035.30Ceramic and glass insulating materialsICS:Ta slovenski standard je istoveten z:EN 60672-1:1995SIST EN 60672-1:1998en01-junij-1998SIST EN 60672-1:1998SLOVENSKI
STANDARD
Ceramic and glass insulating materials – Part 1:
Definitions and classification
For price, see current catalogue IEC 1995 Copyright - all rights reserved No 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 the publisher. International Electrotechnical Commission,
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Web: www.iec.ch INTERNATIONAL STANDARD IEC60672-1 Second edition1995-07 N Commission Electrotechnique InternationaleInternational Electrotechnical CommissionPRICE CODE SIST EN 60672-1:1998

672-1 ©IEC: 1995- 3 -CONTENTSPageFOREWORD 5Clause1 Scope2 Normative references 93Definitions 94Classification of ceramics, glasses, glass-ceramics and glass-bondedmica materials 13Tables 15SIST EN 60672-1:1998

672-1 © IEC: 1995-5-INTERNATIONAL ELECTROTECHNICAL COMMISSIONCERAMIC AND GLASSINSULATING MATERIALS -Part 1: Definitions and classificationFOREWORD1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardizationcomprising all national electrotechnical committees (IEC National Committees). The object of the IEC is topromote international cooperation on all questions concerning standardization in the electrical andelectronic fields. To this end and in addition to other activities, the IEC publishes International Standards.Their preparation is entrusted to technical committees; any IEC National Committee interested inthe subject dealt with may participate in this preparatory work. International, governmental andnon-governmental organizations liaising with the IEC also participate in this preparation. The IECcollaborates closely with the International Organization for Standardization (ISO) in accordance withconditions determined by agreement between the two organizations.2)The formal decisions or agreements of the IEC on technical matters, prepared by technical committees onwhich all the National Committees having a special interest therein are represented, express, as nearly aspossible, an international consensus of opinion on the subjects dealt with.3)They have the form of recommendations for international use published in the form of standards, technicalreports or guides and they are accepted by the National Committees in that sense.4)In order to promote international unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.International Standard IEC 672-1 has been prepared by sub-committee 15C: Specifications,of technical committee 15: Insulating materials.This second edition cancels and replaces the first edition IEC 672-1 (1980) andconstitutes a technical revision. The intention has been to improve the instruction to theuser by defining more clearly the types of material that fall into the individual classes ofthe classification as an aid to their effective selection and use.The class of ceramic insulating materials that has been deleted from the first edition isClass C 830, zirconia ceramics, for the reason that there are no known applications wherezirconia, with its inferior properties to those of alumina, would be used as an insulator.Additional classes of ceramic and glass materials which are in common use for electricalinsulation but which were excluded from the previous edition have been incorporated,specifically:C 140Lithia porcelainsC 430Lime-based porcelainsC 440Zircon porcelainsC 910Aluminium nitridesC 920Boron nitridesC 930Reaction bonded silicon nitrideC 935Dense silicon nitridesSIST EN 60672-1:1998

672-1 © IEC: 1995- 7 -GC 110GC 120GM 110GM 120Glass-ceramics, bulk typeGlass-ceramics, sintered typeGlass-bonded mica, natural mica and glass fritGlass-bonded mica, glass-ceramic typeG795High-silica glass, > 95 % to 99 % SiO2G799High-silica glass, > 99 % SiO2There has been some rationalization of the class numbering for borosilicate glasses:-the former G 200 and G 300 groups have been combined under G 200;-the former group G 200, chemically resistant borosilicate glass, has beenrenumbered G 220;-the former subgroup G 310, low loss electrically resistant glass, has beenrenumbered G 231;-the former subgroup G 320, high voltage electrically resistant glass, has beenrenumbered G 232.The text of this standard is based on the following documents:DISReport on voting
15C/469/DIS15C/542/RVDFull information on the voting for the approval of this standard can be found in the reporton voting indicated in the above table.IEC 672 consists of the following parts, under the general title Ceramic and glassinsulating materials:Part 1: 1995, Definitions and classificationPart 2: 1980, Methods of testPart 3: 1984, Specifications for individual materialsSIST EN 60672-1:1998

672-1 © IEC: 1995- 9 -CERAMIC AND GLASSINSULATING MATERIALS -Part 1: Definitions and classification1 ScopeThis part of IEC 672 is applicable to ceramic, glass-ceramic, glass-mica and glassmaterials for electrical insulating purposes. This part of IEC 672 gives definitions of termsused, and provides tables classifying the various material types into groups according tocompositional type, property attributes and applications.2 Normative referencesThe following normative documents contain provisions which, through reference in thistext, constitute provisions of this part of IEC 672. At the time of publication, the editionsindicated were valid. All normative documents are subject to revision, and parties toagreement based on this part of IEC 672 are encouraged to investigate the possibility ofapplying the most recent editions of the normative documents indicated below. Membersof IEC and ISO maintain registers of currently valid normative documents.IEC 1006: 1991, Methods of test for the determination of the glass-transition temperatureof electrical insulating materials3 DefinitionsFor the purposes of this part of IEC 672, the following definitions apply.3.1 insulating material: A solid with negligibly low electrical conductivity, used toseparate conducting parts of different electrical potentials.3.2 ceramic insulating material: An inorganic material shaped before firing, of whichthe principal constituents usually comprise polycrystalline silicates, aluminosilicates, andsimple or complex oxide compounds, e.g. titanates. The definition also covers certainnon-oxide materials such as aluminium nitride.3.3 glass insulating material: An inorganic material, usually a mixture of oxidesproduced by melting and subsequent solidification essentially without crystallization.3.4 annealed glass: Glass cooled slowly from an elevated temperature so that residualstresses of thermal origin can be neglected in relation to applied stresses.3.5 toughened glass: Glass prepared by pre-stressing such that all body surfaces are ina state of compression, while the interior zone is in tension and is fully protected by thecompressive skin.SIST EN 60672-1:1998

672-1 © IEC: 1995– 11 –3.6 glass-ceramic material: An insulating material derived from bulk glass or glasspowder which has been subjected to a heat treatment so as to induce a substantialamount of crystallinity on a fine scale to render the material a polycrystalline body.3.7 glass-bonded mica material: An insulating material which comprises natural orsynthetic micas in fine particle size bonded with glassy material. Such materials may beproduced by either directly bonding natural mica with a glass frit, or by crystallization of asuitably formulated glass-ceramic.3.8 glaze: A substantially glassy, smooth coating bonded usually by fusion to a ceramicsurface, obtained by melting an applied powder on to a ceramic surface. It may containcolouring and/or opacifying inorganic substances.3.9 porosity: The presence in a body of void space, usually as discrete pores, whichmay be isolated or interconnected.3.10 bulk volume: The total volume measured externally including all open and closedpores.3.11 bulk density (pa): The quotient obtained by dividing the mass of the test specimenby the bulk volume including open and closed pores, expressed in megagrams per cubicmetre (numerically equivalent to grams per cubic centimetre).3.12 open (apparent) porosity (pa): The ratio of the volume of open pores to the bulkvolume, expressed as a percentage.3.13 dye porosity: An indication of liquid absorption by means of dye penetration underpressure. This is often manifested as a general or localized coloration of the surface.Cracks may appear as distinct lines of dye. A distinction should be drawn between surfaceabsorption due to machining or other damage restricted to the immediate surface, andbulk absorption which is immediately apparent if the specimen is fractured.3.14 resistance to thermal shock (AT): A term describing the ability of a material or acomponent to withstand rapid changes of temperature without loss of performance. Thisproperty is normally determined by methods involving transference of a heated specimeninto a cold water bath. The maximum temperature change in kelvins tolerated withoutfracture by a specimen of prescribed dimensions is termed the thermal shock resistancefor the purposes of this standard.3.15 glass transition temperature (T,): The transition of a glass from a rigidnon-equilibrium state at low temperatures fo a viscous liquid state at high temper
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