SIST-TS CEN/TS 15365:2006

Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non-reactive environment - Determination of creep behaviour by the cold end method

This document specifies the conditions for the determination of the tensile creep deformation and failure behaviour of single filaments of ceramic fibres at high temperature and under test conditions that prevent changes to the material as a result of chemical reaction with the test environment.
This document applies to continuous ceramic filaments taken from tows, yarns, braids and knittings, which have strains to fracture less than or equal to 5 %.

Hochleistungskeramik - Mechanische Eigenschaften von Keramikfasern bei hohen Temperaturen in einer reaktionsfreien Umgebung - Bestimmung des Kriechverhaltens im Kaltverbindungsverfahren

Céramiques techniques avancées - Propriétés mécaniques des fibres céramiques a haute température sous environnement non-réactif - Détermination du comportement au fluage par la méthode des mors froids

La présente Spécification technique prescrit les conditions permettant de déterminer la déformation de fluage en traction et le comportement a la rupture de monofilaments de fibres céramiques a température élevée et dans des conditions d’essai empechant toute modification du matériau en raison de la réaction chimique avec le milieu d’essai.
Cette Spécification technique s’applique aux filaments céramiques continus issus de meches, fils, tresses et tricots dont les contraintes a la rupture sont inférieures ou égales a 5 %.

Sodobna tehnična keramika – Mehanske lastnosti keramičnih vlaken pri visokih temperaturah v nereaktivnem okolju – Določitev lezenja po metodi hladnega spajanja (cold end method)

General Information

• Status: Withdrawn
• Publication Date: 30-Jun-2006
• Withdrawal Date: 16-Aug-2010
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 29-Jul-2010
• Due Date: 21-Aug-2010
• Completion Date: 17-Aug-2010
• Ref Project: CEN/TS 15365:2006 - Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non-reactive environment - Determination of creep behaviour by the cold end method

Relations

• Replaced By: SIST EN 15365:2010 - Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non-reactive environment - Determination of creep behaviour by the cold end method
• Effective Date: 01-Sep-2010

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS CEN/TS 15365:2006
01-julij-2006
6RGREQDWHKQLþQDNHUDPLND±0HKDQVNHODVWQRVWLNHUDPLþQLKYODNHQSULYLVRNLK
WHPSHUDWXUDKYQHUHDNWLYQHPRNROMX±'RORþLWHYOH]HQMDSRPHWRGLKODGQHJD
VSDMDQMDFROGHQGPHWKRG
Advanced technical ceramics - Mechanical properties of ceramic fibres at high
temperature in a non-reactive environment - Determination of creep behaviour by the
cold end method
Hochleistungskeramik - Mechanische Eigenschaften von Keramikfasern bei hohen
Temperaturen in einer reaktionsfreien Umgebung - Bestimmung des Kriechverhaltens im
Kaltverbindungsverfahren
Céramiques techniques avancées - Propriétés mécaniques des fibres céramiques a
haute température sous environnement non-réactif - Détermination du comportement au
fluage par la méthode des mors froids
Ta slovenski standard je istoveten z: CEN/TS 15365:2006
ICS:
81.060.30
SIST-TS CEN/TS 15365:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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TECHNICAL SPECIFICATION
CEN/TS 15365
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2006
ICS 81.060.30

English Version
Advanced technical ceramics - Mechanical properties of ceramic
fibres at high temperature in a non-reactive environment -
Determination of creep behaviour by the cold end method
Céramiques techniques avancées - Propriétés mécaniques Hochleistungskeramik - Mechanische Eigenschaften von
des fibres céramiques à haute température sous Keramikfasern bei hohen Temperaturen in einer
environnement non-réactif - Détermination du reaktionsfreien Umgebung - Bestimmung des
comportement au fluage par la méthode des mors froids Kriechverhaltens im Kaltverbindungsverfahren
This Technical Specification (CEN/TS) was approved by CEN on 30 January 2006 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
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, Romania,
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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15365:2006: E
worldwide for CEN national Members.

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CEN/TS 15365:2006 (E)
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions.4
4 Principle.7
5 Significance and use .8
6 Apparatus .8
7 Test specimens .9
8 Test procedures .11
9 Calculation of results.14
10 Test report .15
Bibliography.17

2

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CEN/TS 15365:2006 (E)
Foreword
This Technical Specification (CEN/TS 15365:2006) has been prepared by Technical Committee CEN/TC 184
“Advanced technical ceramics”, the secretariat of which is held by BSI.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.
3

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CEN/TS 15365:2006 (E)
1 Scope
This Technical Specification specifies the conditions for the determination of the tensile creep deformation and
failure behaviour of single filaments of ceramic fibres at high temperature and under test conditions that
prevent changes to the material as a result of chemical reaction with the test environment.
This Technical Specification applies to continuous ceramic filaments taken from tows, yarns, braids and
knittings, which have strains to fracture less than or equal to 5 %.
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.
ENV 13233:1998, Advanced technical ceramics — Ceramic composites - Notations and symbols
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)
3 Terms and definitions
For the purposes of this Technical Specification, the terms and definitions given in ENV 13233:1998 and the
following apply.
3.1
creep
time-dependent increase of gauge length starting from the time when the constant specified level of force is
reached
3.2
creep threshold temperature, T
t
minimum temperature at which creep is detected
3.3
specimen temperature, T
temperature which varies along the fibre length in the cold grips case (see 8.2)
3.4
difference in temperature between the different furnace zones, ∆∆∆∆T
set by the operator
3.5
specimen temperature in the zone, T
i
temperature defined as: T ≤ T ≤ T + i ∆T
t i t
3.6
total length, L
total length of the ceramic filament between the grips
3.7
length, L
i
length of the ceramic filament at temperature T
i
4

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CEN/TS 15365:2006 (E)
3.8
initial effective cross sectional area, A
0

initial cross sectional area of the ceramic filament within the gauge length
3.9
applied tensile force, F
constant force applied to the ceramic filament during the test
3.10
applied tensile stress, σσσσ
applied tensile force divided by the initial cross sectional area
3.11
longitudinal deformation, ∆∆∆∆L
change in the total length of the ceramic filament caused by creep
3.12
longitudinal deformation, ∆∆∆∆L
i
change of the filament caused by creep at temperature T
i
3.13
tensile creep strain, εεεε

cr(T)
relative change in length in the controlled zone at time t, caused by creep at the temperature T
NOTE The value corresponding to rupture is denoted ε .
cr,m
3.14
creep rupture time, t

cr,m
time elapsed from the moment when loading is completed until the moment of rupture
3.15
&
creep strain rate, ε
cr(T)
change in creep strain per unit time at time t at the temperature T
i
3.16
creep types
primary, secondary and tertiary creep
3.17
primary creep
part of the creep strain versus time curve which presents a decreasing creep strain rate (see Figure 1)
3.18
secondary creep
part of the creep strain versus time curve which presents a constant creep strain rate (see Figure 1)
3.19
tertiary creep
part of the creep strain versus time curve which presents an increasing creep strain rate (see Figure 1)

5

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CEN/TS 15365:2006 (E)

a) Creep strain versus time

b) Creep strain rate versus time
Key
6 Creep strain rate ε& (creep strain with time)
1 Creep strain ε
cr
cr
2 Time t 7 Time
3 Primary creep 8 Primary creep
4 Secondary creep 9 Secondary creep
5 Tertiary creep 10 Tertiary creep
Figure 1 — Creep strain and creep strain rate versus time curves
6

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CEN/TS 15365:2006 (E)
4 Principle
A ceramic filament is heated to the test temperature and loaded in tension until a specified level of force. This
force is maintained at a constant level for a specified time or until rupture. The variation in the ceramic filament
length is recorded in relation to time.
The specimen is held in cold grips and heated by a furnace. This experimental configuration provokes
temperature variations along the filament, which have to be taken into account in order to determine the creep
properties as function of temperature. Prior to testing, the temperature profile inside the furnace is established
over the temperature range. The temperature range is then divided into several temperature zones defined by
the operator, according to the following graph.

Key
T Temperature (°C)
l Length of the furnace
P Position (mm)
En Entrance
Ex Exit
Figure 2 — Temperature profile in furnace
If T is considered to be the lowest temperature at which creep is observed, the temperature profile can be
t
divided in several intervals as a function of T and ∆T, where ∆T is the difference in temperature between the
t
different zones, fixed by the operator.
If we consider i, the entire number of zones, and L, the total fibre length, then we can define the following
lengths:
 L is the furnace length where the temperature T is in the range 20 °C ≤ T ≤ T ;
20 t
 L is the furnace length where the temperature T is in the range T ≤ T ≤ T + ∆T ;
∆T t t
 L is the furnace length where the temperature T is in the range T + ∆T ≤ T ≤ T + 2 ∆T ;
2∆T t t
 L is the furnace length where the temperature T is in the range T + (i – 1) ∆T ≤ T ≤ T + i ∆T.
i∆T t t
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CEN/TS 15365:2006 (E)
Then L can be written:
L = L + L + L + L + … + L (1)
20 ∆T 2∆T 3∆T i∆T
Thus it is possible to determine the deformation in all of these different temperature zones. The inconvenience
of this method is that determining the true deformation in the L zone requires the determination of the
2∆T
deformation in the lower temperature zones.
Below the temperature T and for a constant load applied to the fibre, the deformation is constant so that the
t
strain rate is equal to zero.
5 Significance and use
Creep tests allow the comparison and the determination of parameters or behaviour laws and their
extrapolation to long-term behaviour for different materials under constant load at high temperatures. These
allow the conception and design of industrial parts with close control of tolerances for high temperature
applications.
6 Apparatus
6.1 Test installations
NOTE Two different types of installation can be used, as specified in 6.1.1 and 6.1.2.
6.1.1 Test machine
The machine shall be equipped with a system for measuring the force applied to the test specimen. The
-3
machine shall have a load cell with a resolution of 10 N for the applied force. The displacement transducer
shall have a resolution of at least 2 µ. This shall prevail during actual test conditions (pressure, temperature).
6.1.2 Creep testing rig
When a creep testing rig is used, the force application system shall be calibrated. The testing rig shall be
equipped with a system to allow smooth loading of the ceramic filament(s). When this system is used, care
-3
shall be taken to ensure that the force applied to the ceramic filament remains constant to within 10 N, even
when the material properties change and the environmental conditions (temperature, pressure) fluctuate.
6.2 Load train
The gripping system shall align the test specimen axis with that of the applied force.
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 and the force
transmission shall not change because of heating.
6.3 Test chamber
6.3.1 General
The chamber shall allow proper control of the test specimen environment during the test and ensure that any
variation of load during the test is less than 1 % of the scale of the load cell being used.
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CEN/TS 15365:2006 (E)
6.3.2 Gaseous environment
The gaseous environment shall be chosen depending on the material to be tested and on the test temperature.
If the test is conducted in flowing gas, the rate of flow should be sufficiently high to exclude oxygen, but not so
as to induce turbulence in the furnace. If a closed system is used 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.
6.3.3 Vacuum chamber
The level of vacuum shall not induce chemical and/or physical instabilities of the filament.
6.4 Set-up for
...