SIST EN 12290:2005

SLOVENSKI STANDARD
SIST EN 12290:2005
01-november-2005
1DGRPHãþD
SIST ENV 12290:2000
Advanced technical ceramics - Mechanical properties of ceramic composites at
high temperature under inert atmosphere - Determination of compression
properties
Advanced technical ceramics - Mechanical properties of ceramic composites at high
temperature under inert atmosphere - Determination of compression properties
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei hoher Temperatur in inerter Atmosphäre - Bestimmung der
Eigenschaften unter Druck
Céramiques techniques avancées - Propriétés mécaniques des céramiques composites
a haute température en atmosphere neutre - Détermination des caractéristiques en
compression
Ta slovenski standard je istoveten z: EN 12290:2005
ICS:
81.060.30 Sodobna keramika Advanced ceramics
SIST EN 12290:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 12290:2005

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SIST EN 12290:2005



EUROPEAN STANDARD
EN 12290

NORME EUROPÉENNE

EUROPÄISCHE NORM
June 2005
ICS 81.060.30 Supersedes ENV 12290:1996
English version
Advanced technical ceramics - Mechanical properties of ceramic
composites at high temperature under inert atmosphere -
Determination of compression properties
Céramiques techniques avancées - Propriétés mécaniques Hochleistungskeramik - Mechanische Eigenschaften von
des céramiques composites à haute température en keramischen Verbundwerkstoffen bei hoher Temperatur in
atmosphère neutre - Détermination des caractéristiques en inerter Atmosphäre - Bestimmung der Eigenschaften unter
compression Druck
This European Standard was approved by CEN on 12 May 2005.

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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.




EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12290:2005: E
worldwide for CEN national Members.

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SIST EN 12290:2005
EN 12290:2005 (E)
Contents page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms, definitions and symbols.4
4 Principle.6
5 Apparatus .6
5.1 Test machine.6
5.2 Load train.6
5.3 Gastight test chamber.7
5.4 Set-up for heating .7
5.5 Extensometer .7
5.6 Temperature measurement devices .7
5.7 Data recording system .8
5.8 Micrometers.8
6 Test specimens.8
6.1 General.8
6.2 Compression between platens.8
6.3 Test specimen used with grips .9
7 Test specimen preparation.12
7.1 Machining and preparation.12
7.2 Number of test specimens.12
8 Test procedures.12
8.1 Test set-up: Temperature considerations.12
8.2 Test set-up: other considerations.13
8.3 Testing technique .14
8.4 Test validity .15
9 Calculation of results .15
9.1 Test specimen origin.15
9.2 Compression strength .15
9.3 Strain at maximum compression force .16
9.4 Proportionality ratio or pseudo-elastic modulus, elastic modulus .16
10 Test report .17
Annex A (normative) Buckling: How to proceed when buckling is suspected.18
A.1 Preliminary room temperature test.18
A.2 Test with two different specimens.18
Bibliography .19

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SIST EN 12290:2005
EN 12290:2005 (E)
Foreword
This document (EN 12290:2005) 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 December 2005, and conflicting national standards shall be withdrawn
at the latest by December 2005.
This document supersedes ENV 12290:1996.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
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SIST EN 12290:2005
EN 12290:2005 (E)
1 Scope
This European Standard specifies the conditions for determination of compression properties of ceramic
matrix composite materials with continuous fibre reinforcement for temperatures up to 2 000 °C under vacuum
or a gas atmosphere which is inert to the material under test.
NOTE The use of these environments is aimed at avoiding changes of the material to be tested due to chemical
reaction with its environment during the test.
This European Standard applies to all ceramic matrix composites with a continuous fibre reinforcement,
unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x ≤ 3), loaded along one principal axis of
reinforcement.
Two types of compression are distinguished:
a) compression between platens;
b) compression using grips.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 10002-4, Metallic materials - Tensile test - Part 4: Verification of extensometers used in uniaxial testing.
EN 60584-1, Thermocouples - Part 1: Reference tables (IEC 60584-1:1995).
EN 60584-2, Thermocouples — Part 2: Tolerances (IEC 60584-2:1982 + A1:1989).
EN ISO 7500-1, Metallic materials — Verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Verification and calibration of the force measuring system (ISO
7500-1:2004).
ISO 3611, Micrometer callipers for external measurement.
3 Terms, definitions and symbols
For the purposes of this European Standard, the following terms and definitions apply.
3.1
test temperature, T
temperature of the test piece at the centre of the gauge length
3.2
calibrated length, l
part of the test specimen that has uniform and minimum cross-section area
3.3
gauge length, L
o
initial distance between reference points on the test specimen in the calibrated length
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SIST EN 12290:2005
EN 12290:2005 (E)
3.4
controlled temperature zone
part of the calibrated length including the gauge length where the temperature is within a range of 50 °C of the
test temperature
3.5
initial cross-section area, A
o
initial cross-section area of the test specimen within the calibrated length, at test temperature
3.6
longitudinal deformation, ∆∆∆∆ L
decrease in the gauge length L between reference points under a compression force
NOTE Its value at maximum force is denoted ∆ L .
c,m
3.7
compression strain, ∈∈∈∈
relative change in the gauge length defined as the ratio ∆ L/L
o
NOTE Its value at maximum force is denoted as ∈ .
c,m
3.8
compression stress, σσσσ
compression force supported by the test specimen at any time in the test divided by the initial cross-section
area (A )
o
3.9
maximum compression force, F
m
highest recorded compression force in a compression test on the test specimen when tested to failure
3.10
compression strength, σσσσ
c,m
ratio of the maximum compression force (F ) to the initial cross-section area (A )
m o
3.11
proportionality ratio or pseudo-elastic modulus, E
p
slope of the linear section of the stress-strain curve, if any
NOTE Examination of the stress-strain curves for ceramic matrix composites allows definition of the following cases:
a) Material with a linear section in the stress-strain curve.
For ceramic matrix composites that have a mechanical behaviour characterized by a linear section, the proportionality
ratio is defined as:
σ − σ
2 1
Ep (σ , σ ) = (1)
1 2
ε − ε
2 1
where
(∈ , σ ) and (∈ , σ ) lie near the lower and upper limits of the linear section of the stress-strain curve.
1 2 2 2
The proportionality ratio or pseudo-elastic modulus is termed the elastic modulus, E, in the single case where the material
has a linear behaviour from the origin.
b) Material with no-linear section in the stress-strain curve.
In this case only stress-strain couples can be fixed.
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SIST EN 12290:2005
EN 12290:2005 (E)
4 Principle
A test specimen of specified dimensions is heated to the test temperature, and loaded in compression. The
test is performed at constant crosshead displacement rate, or constant deformation rate. Force and
longitudinal deformation are measured and recorded simultaneously.
NOTE 1 The test duration is limited to reduce creep effects.
NOTE 2 Constant loading rate is only allowed in the case of linear stress-strain behaviour up to failure.
NOTE 3 In order to protect fixtures, it is recommended to use constant crosshead displacement rate when the test is
carried out until rupture.
5 Apparatus
5.1 Test machine
The machine shall be equipped with a system for measuring the force applied to the test specimen which shall
conform to grade 1 or better according to EN ISO 7500-1.
NOTE This should prevail during actual test conditions of, e.g. gas pressure and temperature.
5.2 Load train
The load train configuration shall ensure that the load indicated by the load cell and the load experienced by
the test specimen are the same.
The load train performance including the alignment system and the force transmitting system shall not change
because of heating.
There are two alternative means of load application.
a) Compression platens are connected to the load cell and on the moving crosshead. The parallelism of
these platens shall be better than 0,01 mm, in the loading area, at room temperature and they shall be
perpendicular to the load direction.
NOTE 1 The use of platens is not recommended for compression testing of 1D and 2D materials with low thickness
due to buckling.
NOTE 2 A compliant interlayer material between the test specimen and platens may be used for testing
macroscopically inhomogeneous materials to ensure even contact pressure. This material should be chemically
compatible with both test specimen and platen materials.
b) Grips are used to clamp and load the test specimen.
The grip design shall prevent the test specimen from slipping. The grips shall align the test specimen axis with
that of the applied force.
NOTE 3 Conformity with this requirement should be verified and documented according to, for example, the procedure
described in reference [1].
NOTE 4 The grips or the platens may either be in the hot zone of the furnace or outside the furnace.
NOTE 5 When grips or platens are outside the furnace, a temperature gradient exists between the centre of the
specimen, which is at the prescribed temperature, and the ends that are at the same temperature as the grips or platens.
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SIST EN 12290:2005
EN 12290:2005 (E)
5.3 Gastight test chamber
The gastight chamber shall allow proper control of the test specimen environment in the vicinity of the test
specimen during the test. The installation shall be such that the variation of load due to the variation of
pressure is less than 1 % of the scale of the load cell being used.
Where a gas atmosphere is used, the gas atmosphere shall be chosen depending on the material to be tested
and on test temperature. The level of pressure shall be chosen depending: on the material to be tested, on
temperature, on the type of gas, and on the type of extensometry.
Where a vacuum chamber is used, the level of vacuum shall not induce chemical and/or physical instabilities
of the test specimen material, and of extensometer rods, when applicable.
5.4 Set-up for heating
The set-up for heating shall be constructed in such a way that the temperature gradient within the gauge
length is less than 20 °C at test temperature.
5.5 Extensometer
The extensometer shall be capable of continuously recording the longitudinal deformation at test temperature.
NOTE 1 The use of an extensometer with the greatest possible gauge length is recommended.
The linearity tolerance shall be less than or equal to 0,15 % of the extensometer range used.
The extensometer shall conform to class 1 or better of EN 10002-4. Two commonly used types of
extensometer are the mechanical extensometer and the electro-optical extensometer.
If a mechanical extensometer is used, the gauge length shall be the initial longitudinal distance between the
two locations where the extensometer rods contact the test specimen.
The rods may be exposed to temperatures higher than the test specimen temperature. Temperature and/or
environment induced structural changes in the rod material shall not affect the accuracy of deformation
measurement. The material used for the rods shall be compatible with the test specimen material.
NOTE 2 Care should be taken to correct for changes in calibration of the extensometer that may occur as a result of
operating under conditions different from calibration.
NOTE 3 Rod pressure onto the test specimen should be the minimum necessary to prevent slipping of the
extensometer rods.
If an electro-optical extensometer is used, electro-optical measurements in transmission require reference
m
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