www bzfxw com Copyright British Standard Reproduced by IHS under BRITISH STANDARD BS EN 1159 1 2003 Advanced technical ceramics — Ceramic composites — Thermophysical properties — Part 1 Determination[.]
Trang 1BRITISH STANDARD BS EN
1159-1:2003
Advanced technical ceramics — Ceramic composites —
Thermophysical properties —
Part 1: Determination of thermal expansion
The European Standard EN 1159-1:2003 has the status of a British Standard
ICS 81.060.30
12&23<,1*:,7+287%6,3(50,66,21(;&(37$63(50,77('%<&23<5,*+7/$:
Copyright British Standards Institution
Reproduced by IHS under license with BSI - Uncontrolled Copy
Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:15:31 MST Questions or comments about this message: please call the Document
Trang 2
`,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` -This British Standard was
published under the authority
of the Standards Policy and
Strategy Committee on
10 February 2004
© BSI 10 February 2004
ISBN 0 580 43383 8
National foreword
This British Standard is the official English language version of
EN 1159-1:2003 It supersedes DD ENV 1159-1:1994 which is withdrawn The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics, which has the responsibility to:
A list of organizations represented on this committee can be obtained on request to its secretary
Cross-references
The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or
by using the “Search” facility of the BSI Electronic Catalogue or of
British Standards Online
This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application
Compliance with a British Standard does not of itself confer immunity from legal obligations.
— aid enquirers to understand the text;
— present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the
UK interests informed;
— monitor related international and European developments and promulgate them in the UK
Summary of pages
This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 15 and a back cover
The BSI copyright notice displayed in this document indicates when the document was last issued
Amendments issued since publication
Trang 3EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
EN 1159-1
July 2003
English version
Advanced technical ceramics Ceramic composites -Thermophysical properties - Part 1: Determination of thermal
expansion
Céramiques techniques avancées - Céramiques composites - Propriétés thermophysiques - Partie 1:
Détermination de la dilatation thermique
Hochleistungskeramik Keramische Verbundwerkstoffe -Thermophysikalische Eigenschaften - Teil 1: Bestimmung
der thermischen Ausdehrung
This European Standard was approved by CEN on 23 May 2003.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
C O M I T É E U R O P É E N D E N O R M A L I S A T I O N
E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved
worldwide for CEN national Members.
Ref No EN 1159-1:2003 E
Copyright British Standards Institution
Reproduced by IHS under license with BSI - Uncontrolled Copy
Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:15:31 MST Questions or comments about this message: please call the Document
Trang 4Foreword 3
1 Scope 4
2 Normative references 4
3 Terms and definitions 4
4 Principle 5
4.1 General 5
4.2 Direct measurement 5
4.3 Differential method 5
5 Apparatus 5
5.1 Construction materials 5
5.2 Heating and cooling device 5
5.3 Temperature measurement 5
5.4 Test piece mounting 5
5.5 System for measuring and recording the thermal expansion 6
5.6 Test piece measurement 6
6 Specimens 6
6.1 Test pieces 6
6.2 Reference pieces 6
6.3 Dimensions 7
7 Procedure 7
8 Calculations 7
8.1 Direct measurement 7
8.2 Differential method 8
9 Test report 9
Annex A (normative) Direct measurement apparatus 12
A.1 Determination of measurement sensitivity 12
A.2 Determination of A 13
Annex B (normative) Differential type measurement apparatus 14
B.1 Determination of measurement sensitivity S 14
B.2 Determination of 14
Bibliography 15
Trang 5
EN 1159-1:2003 (E)
3
Foreword
This document (EN 1159-1:2003) has been prepared by Technical Committee CEN /TC 184, "Advanced technical
ceramics" the secretariat of which is held by BSI
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by January 2004, and conflicting national standards shall be withdrawn at the latest
by January 2004
This document supersedes ENV 1159-1:1993
EN 1159 'Advanced technical ceramics – Ceramic composites – Thermophysical properties' consists of four parts :
Part 1 : Determination of thermal expansion
Part 2 : Determination of thermal diffusivity
Part 3 : Determination of specific heat capacity
Part 4: Determination of thermal conductivity
Annexes A and B are normative
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,
Slovakia, Spain, Sweden, Switzerland and the United Kingdom
Copyright British Standards Institution
Reproduced by IHS under license with BSI - Uncontrolled Copy
Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:15:31 MST Questions or comments about this message: please call the Document
Trang 6
4
1 Scope
This Part of EN 1159 describes methods for the determination of linear thermal expansion characteristics of
ceramic matrix composite materials up to 2 300 K, and is applicable to 10, 2D and nD materials
The method describes general principles of construction calibration and operation of the equipment
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision For undated references the latest edition of the
publication referred to applies (including amendments)
EN 821-1, Advanced technical ceramics - Monolithic ceramics - Thermo-physical properties - Part 1 : Determination
of thermal expansion
EN 60584-1, Thermocouples – Part 1: Reference tables (IEC 60584-1:1995)
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC
17025:1999)
ISO 3611, Micrometer callipers for external measurement
ISO 6906, Vernier callipers reading to 0,02 mm
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply
3.1
linear thermal expansion
positive or negative change in one dimension that occurs when a material is subjected to a change in temperature
3.2
linear thermal expansion coefficient at temperature T
derivative of the length L with respect to temperature at the temperature T, divided by the length at temperature T
T dT
dL
1
T
3.3
mean linear thermal expansion coefficient between temperatures T1 and T2
linear thermal expansion between temperatures T1 and T2 divided by the temperature increment T1 to T2 and the
length at temperature T1
1
1 2 2 1
T L
T L T L T
T ,
3.4
representative volume element (R.V.E.)
minimum volume which is representative of the material considered
Trang 7EN 1159-1:2003 (E)
5
4 Principle
4.1 General
A test piece is heated and subsequently cooled, either at a specified uniform rate or using defined temperature
increments Its change of length and its temperature are measured continuously or at regular frequent intervals
during the imposed temperature cycle
One of two methods may be used to determine the linear thermal expansion coefficient, either by direct
measurement or by a differential method
4.2 Direct measurement
In this method the variation in length of the test piece is measured directly It is necessary to know the change in
dimensions of the test piece support system by previous calibration
The test piece is placed in a specimen holder and is made to contact a displacement transducer by using a push
rod made of the same material as the holder This assembly is put in a furnace The differential expansion between
the test piece and the test piece holder is measured during the increase and the decrease in temperature
The apparatus is shown in Figure 1
4.3 Differential method
This method consists of measuring the changes in length between a reference piece (see 6.2) and the test piece
Its is not therefore necessary to know the change in dimensions of the test piece support system
The apparatus is shown in Figure 2
5 Apparatus
5.1 Construction materials
The test piece holder and the push rod shall be made from thermomechanically stable materials of the same type,
which shall be chemically inert and thermally compatible with the test piece material under the environmental
conditions of the test
NOTE For temperatures above 1 400 °C, it is necessary to employ a vacuum or inert gas atmosphere, with a non-oxide
material appropriate for the test environment, such as a grade of dense graphite
5.2 Heating and cooling device
Furnace, capable of working in a controlled atmosphere when required, and of controlling the temperature of the
test piece to within 1 % of its mean temperature, expressed in K
5.3 Temperature measurement
Thermocouples, in accordance with EN 60584-1, subject to the upper temperature requirements and environmental
consideration, except for tungsten-rhenium couples which may be used at higher temperatures, but are not
covered by EN 60584-1 should be individually calibrated For temperature in excess of 2 000 K, infrared detectors
or any suitable device may be used
5.4 Test piece mounting
The device used shall allow free axial movement of the test piece and of the reference piece in case of differential
measurement The mechanical environment shall minimize stresses For vertical measurement apparatus, the test
pieces shall be free standing and mechanically stable on the end-plate For measuring apparatus which is
Copyright British Standards Institution
Reproduced by IHS under license with BSI - Uncontrolled Copy
Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:15:31 MST Questions or comments about this message: please call the Document
Trang 8
6
horizontal or inclined to the horizontal, the sideways movement or twist of the test piece shall be restricted, without
any restriction of axial movement, by a suitable arrangement
5.5 System for measuring and recording the thermal expansion
System, capable of measuring displacements to an accuracy better than 0,1 m The system shall allow recording
of the test piece temperauture and the displacement simultaneously The system for measuring of displacements
shall be periodically calibrated in accordance with annex A for direct measurement or annex B for differential
measurement
5.6 Test piece measurement
Device for measuring the test piece dimensions, with an accuracy better than 0,05 mm (e.g micrometer in
accordance with ISO 3611 or callipers in accordance with ISO 6906)
6 Specimens
6.1 Test pieces
The dimensions of the test pieces depend on the type of apparatus used For differential measurements the test
piece and the reference piece (see 6.2) shall have the same length L0 (see Table 1)
The test piece shall be cut in such a way that the axis of desired measurement is related to the principal fibre
orientations in accordance with agreement between parties to the measurement
The end-faces of the length of the test piece shall be plane, parallel to each other and perpendicular to the long
axis
6.2 Reference pieces
Reference materials shall be chosen so that their properties are as close as possible to the properties of the
material to be tested The reference piece shall have a volume of the same order and if possible shall have the
same dimensions as the test piece (see Table 1)
For measurement at high temperature (over 2 000 K) under inert atmosphere, reference materials generally used
are either tungsten or highly purified graphite Reference materials shall be procured from a certified laboratory
NOTE NIST in the USA is one laboratory which supplies reference materials Highly purified 'POCO' graphite is largely
used as a reference for measurement at high temperature
Trang 9EN 1159-1:2003 (E)
7
6.3 Dimensions
Table 1 — Recommended test piece dimensions
Dimensions in millimeters
Material with small R.V.E.
(see 3.4) such as 1D or 2D
Material with large R.V.E.
(see 3.4) such as nD Tolerances
-h, thickness Depending on material and
equipment
Depending on material and equipment
Depending on material and equipment
-NOTE 1 A test piece volume of a minimum of 5 R.V.E is recommended (see 3.4)
NOTE 2 The shape and dimensions of the test piece depend on the structure of reinforcement In the case of material such
as 3D, a large test piece is often necessary when the representative volume element is important
7 Procedure
In order to simplify calibration procedures, test pieces and reference pieces of the same length should be used If
reference and test pieces have different lengths, then it is necessary to take into account a base line shift In this
case, refer to EN 821-1
Measure the original length of the test piece at room temperature to an accuracy better than 0,2 mm
Make sure that the equipment has been calibrated for the type of material prior to the test, according to the
procedure described in annex A for direct measurement [determination of S and A] and in annex B for
differential measurement (determination of S and ) If the test is to be performed in an inert or vacuum
environment, establish the environment before commencing heating
Position the test piece in the equipment and proceed with heating or cooling at a rate of between 1 K/min and
5 K/mins, ensuring a fairly constant temperature gradient along and through the test piece If the temperature is
changed in steps, the hold temperature shall be maintained until the length of the test piece shows no change for a
period of 5 mins
In case of large test pieces, a stepwise temperature rise is recommended
The mean linear thermal expansion coefficient shall be calculated as the average from the results of tests on three
test pieces
8 Calculations
8.1 Direct measurement
Calculate the change in length, l, of a length of the sample holder material equal to the original test piece length
L0, from the expression :
2 1
0 T T L
l A
using the calculated value of l, obtain the change in length of l of the test piece from the measured displacement
by S x :
Copyright British Standards Institution
Reproduced by IHS under license with BSI - Uncontrolled Copy
Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:15:31 MST Questions or comments about this message: please call the Document
Trang 108
l x S
Calculate the mean linear thermal expansion coefficient of the test piece material from the expression:
2 1
0 T T L
l
where
is the mean linear thermal expansion coefficient of the test piece material, in K-1;
A
is the mean linear thermal expansion coefficient correction for the apparatus over the temperature
range used It is determined from calibration (see annex A);
L0 is the initial length of the test piece at room temperature, in mm;
x is the recorded displacement (in mm, volt, etc.) over the temperature range;
S is the measurement sensitivity of the displacement recording system;
l is the change in length of the sample holder material, in mm;
L is the change in length of the test piece in mm;
T2 – T1 is the temperature internal in K for which the change in length is measured
A curve of
0
L L
versus T may be constructed.
8.2 Differential method
Calculate the mean linear thermal expansion coefficient of the test piece material from the expression:
2 1 0
R L R T
T L
x S
where
is the baseline correction over the temperature range, which is introduced because of the possibility of
unequal response from the two pushrods;
)
(R
L is the initial reference piece length in mm at room temperature;
)
(R
is the mean linear thermal expansion coefficient of the reference piece in K-1
and other terms are as in 8.1