EN 1893:2005

SLOVENSKI STANDARD
01-september-2005
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Advanced technical ceramics - Mechanical properties of ceramic composites at high
temperature in air at atmospheric pressure - Determination of tensile properties
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei hoher Temperatur in Luft bei Atmosphärendruck - Bestimmung
der Eigenschaften unter Zug
Céramiques techniques avancées - Propriétés mécaniques des céramiques composites
a haute température sous air a la pression atmosphérique - Détermination des
caractéristiques en traction
Ta slovenski standard je istoveten z: EN 1893:2005
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 1893
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2005
ICS 81.060.30 Supersedes ENV 1893:1996
English version
Advanced technical ceramics - Mechanical properties of ceramic
composites at high temperature in air at atmospheric pressure -
Determination of tensile properties
Céramiques techniques avancées - Propriétés mécaniques Hochleistungskeramik - Mechanische Eigenschaften von
des céramiques composites à haute température sous air à keramischen Verbundwerkstoffen bei hoher Temperatur in
la pression atmosphérique - Détermination des Luft bei Atmosphärendruck - Bestimmung der
caractéristiques en traction Eigenschaften unter Zug
This European Standard was approved by CEN on 15 March 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 1893:2005: E
worldwide for CEN national Members.

Contents
Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms, definitions and symbols.4
4 Principle.6
5 Apparatus .6
6 Test specimens.8
7 Test specimen preparation.10
8 Test procedures.11
9 Calculation of results .13
10 Test report .15
Annex A (informative) Test specimen for use with optical extensometry.16
Bibliography .17

Foreword
This document (EN 1893:2005) 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 October 2005, and conflicting national standards shall be withdrawn at
the latest by October 2005.
This document supersedes ENV 1893:1996.
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.
1 Scope
This document specifies the conditions for determination of tensile properties of ceramic matrix composite
materials with continuous fibre reinforcement for temperatures up to 1 700 °C in air at atmospheric pressure.
This document applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional
(1D), bi-directional (2D), and tri-directional (xD, with 2 < x ≤ 3), loaded along one principal axis of
reinforcement.
NOTE 1 In most cases, ceramic matrix composites to be used at high temperature in air are coated with an anti-
oxidation coating.
NOTE 2 The purpose of this document is to determine the tensile properties of a material when it is placed under an
oxidizing environment but not to measure material oxidation.
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 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 document, the following terms, definitions and symbols apply.
3.1
test temperature, T
temperature of the test piece at the centre of the gauge length
3.2
calibrated length, I
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
3.4
controlled temperature zone
part of the calibrated length including the gauge length where the temperature is controlled to within 50 °C of
the test temperature
3.5
initial cross-section area, S
o
initial cross-section areas of the test specimen within the calibrated length, at test temperature
3.6
apparent cross-section area, S
o app
total area of the cross-section

3.7
effective cross-section area, S
o eff
total area corrected by a factor, to account for the presence of an anti-oxidative protection
3.8
longitudinal deformation, A
increase in the gauge length between reference points under a tensile force
3.9
longitudinal deformation under maximum tensile force, A
m
increase in the gauge length between reference points under maximum tensile force
3.10
tensile strain, ∈
relative change in the gauge length defined as the ratio A/L
o
3.11
tensile strain under maximum force, ∈ .
m
relative change in the gauge length defined as the ratio A/L under the maximum force
o
3.12
tensile stress, σ
tensile force supported by the test specimen at any time in the test divided by the initial cross-section area (S )
o
3.13
apparent tensile stress, σ
app
tensile force supported by the test specimen at any time in the test divided by the apparent cross-section area
(or total cross-section area)
3.14
effective tensile stress, σ
eff
tensile force supported by the test specimen at any time in the test divided by the effective cross-section area
(S )
o eff
3.15
maximum tensile force, F
m
highest recorded tensile force in a tensile test on the test specimen when tested to failure
3.16
3.16.1
tensile strength, σ
m
ratio of the maximum tensile force to the initial cross-section area (S )
o
3.16.2
apparent tensile strength, σ
m app
ratio of the maximum tensile force to the apparent cross-section area (or total cross-section area)
3.16.3
effective tensile strength,
σ
m eff
ratio of the maximum tensile force to the effective cross-section area
3.17
proportionality ratio or pseudo-elastic modulus EP
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
()∈ −∈
2 1
where
()∈ ,σ and()∈ ,σ lie near the lower and the 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 linearity
starts near the origin.
b) material with no-linear section in the stress-strain curve.
In this case only stress-strain couples can be fixed.
3.18
apparent proportionality ratio, EP
app
slope of the linear section of the stress-strain curve, if any, when the apparent tensile stress is used
3.19
effective proportionality ratio, EP
eff
slope of the linear section of the stress-strain curve, if any, when the effective tensile stress is used
4 Principle
A test specimen of specified dimensions is heated to the test temperature, and loaded in tension. The test is
performed at constant crosshead displacement rate, or constant deformation rate (or constant loading rate).
Force and longitudinal deformation are measured and recorded simultaneously.
NOTE 1 The test duration is limited to reduce creep effects.
NOTE 2 When constant loading rate is used in the non-linear region of the tensile curve, only the tensile strength can
be obtained from the test. In this region constant crosshead displacement rate or constant deformation rate is
recommended to obtain the complete curve.
5 Apparatus
5.1 Test machine
The test machine shall be equipped with a system for measuring the force applied to the test specimen
conforming to grade 1 or better according to EN ISO 7500-1.
NOTE This prevails during actual test conditions, e.g. gas pressure, 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.
The attachment fixtures shall align the test specimen axis with the applied force direction.
NOTE 1 The alignment should be verified and documented in accordance with, for example, the procedure described
in the HTMTC code of practice [1].
The grip design shall prevent the test specimen from slipping.
There are two types of gripping systems:
 hot grips where the grips are in the hot zone of the furnace;
 cooled grips where the grips are outside the hot zone.
NOTE 2 The choice of gripping system will depend on material, on test specimen design and on alignment
requirements.
NOTE 3 The hot grip technique is limited in temperature because of the nature and strength of the materials that can
be used for grips.
NOTE 4 In the cooled grip technique, a temperature gradient exists between the centre which is at the prescribed
temperature and the ends which are at the same temperature as the grips.
5.3 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.
5.4 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 gauge length is recommended.
The linearity tolerances shall be lower than 0,05 % of the extensometer range used.
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 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 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
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