EN 15365:2025

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

Dieses Dokument legt die Bedingungen für die Bestimmung der Kriechzugdehnung und des Fehlerverhaltens von einzelnen Fasern von Keramikfasern bei hohen Temperaturen und Prüfbedingungen, die Anderungen des Werkstoffs aufgrund chemischer Reaktionen mit der Prüfumgebung verhindern, fest.
Dieses Dokument ist anwendbar auf Endlos-Keramikfasern aus Bündeln, Garnen, Borten und Maschenwaren, die eine Bruchdehnung von weniger als oder gleich 5% aufweisen.

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

Le présent document spécifie les conditions permettant de déterminer la déformation de fluage en traction et le comportement à la rupture de monofilaments de fibres céramiques à température élevée et dans des conditions d’essai empêchant toute modification du matériau en raison de la réaction chimique avec le milieu d’essai.
Le présent document s’applique aux filaments céramiques continus issus de mèches, fils, tresses et tricots dont les contraintes à la rupture sont inférieures ou égales à 5 %.

Sodobna tehnična keramika - Mehanske lastnosti keramičnih vlaken pri visokih temperaturah v nereaktivnem okolju - Ugotavljanje lezenja po metodi hladnega spajanja

General Information

• Status: Published
• Publication Date: 09-Dec-2025
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: CEN/TC 184 - Advanced technical ceramics
• Drafting Committee: CEN/TC 184/SC 1 - Ceramic composites
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 10-Dec-2025
• Due Date: 11-Jan-2026
• Completion Date: 10-Dec-2025
• Ref Project: SIST EN 15365:2026 - Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non-reactive environment - Determination of creep behaviour by the cold grip method

Relations

• Replaces: 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: 04-Oct-2023

Overview

EN 15365:2025 (CEN) - "Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non‑reactive environment - Determination of creep behaviour by the cold grip method" - specifies a standardized method to measure the tensile creep deformation and failure behaviour of single ceramic filaments under high temperature in an environment that prevents chemical reaction (non‑reactive/inert). It applies to continuous ceramic filaments taken from tows, yarns, braids and knittings with strains to fracture ≤ 5 %. EN 15365:2025 supersedes EN 15365:2010.

Key topics and technical requirements

• Test principle: a single filament is mounted in cold grips, heated by a furnace, loaded to a constant tensile force and the change in length is recorded versus time to produce creep curves.
• Temperature profile & zoneing: because cold grips create a longitudinal temperature gradient along the filament, the standard requires determination of the furnace temperature profile and division into temperature zones for accurate creep-versus-temperature analysis.
• Specimens: continuous single filaments extracted from commercial tows/yarns; applicability limited to filaments with fracture strain ≤ 5 %.
• Apparatus & measurement accuracy:
  • Load cell resolution: 10 N (and force stability within ±10 N for some rig types).
  • Displacement transducer resolution: ≥ 2 µm under test conditions.
  • Load variation during test: kept below 1 % of load cell scale.
  • Control and recording systems to monitor temperature, force and displacement continuously.
• Gaseous environment: tests performed in a non‑reactive (inert) atmosphere or closed system; flow rates and pressure must be selected to avoid oxidation or gas‑induced reactions while keeping furnace stability.
• Results & calculations: derivation of creep stress, creep strain vs time, creep strain rate, creep rupture time and strain at rupture. Validity criteria and specific procedures for data processing and test reporting are defined.
• Normative reference: EN 60584 (thermocouples) is referenced for temperature measurement.

Practical applications

EN 15365 is used to:

• Characterize high‑temperature mechanical performance of ceramic fibre filaments for use in composites, thermal insulation, filtration media and advanced structural components.
• Provide data for creep models, lifetime extrapolation and design of high‑temperature assemblies.
• Support material selection and quality control for industries where ceramic fibres operate at elevated temperatures (aerospace, power generation, industrial furnaces, automotive turbochargers, defence).

Who should use this standard

• Materials laboratories and R&D teams developing advanced technical ceramics and high‑temperature fibres.
• Manufacturers of ceramic fibres, tows and high‑temperature textiles for specification and QC.
• Design and engineering teams assessing long‑term creep behaviour and durability of fibre‑reinforced components.
• Test houses and certification bodies performing standardized high‑temperature creep tests.

Related standards

• EN 60584 (thermocouples) - normative reference for temperature measurement.
• (EN 15365:2025 formally replaces EN 15365:2010)

Keywords: EN 15365, ceramic fibres, creep behaviour, cold grip method, high temperature, non‑reactive environment, tensile creep, continuous ceramic filaments, creep testing, advanced technical ceramics, CEN.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2026
Sodobna tehnična keramika - Mehanske lastnosti keramičnih vlaken pri visokih
temperaturah v nereaktivnem okolju - Ugotavljanje lezenja po metodi hladnega
spajanja
Advanced technical ceramics - Mechanical properties of ceramic fibres at high
temperature in a non-reactive environment - Determination of creep behaviour by the
cold grip 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 à
haute température sous environnement non réactif - Détermination du comportement au
fluage par la méthode des mors froids
Ta slovenski standard je istoveten z: EN 15365:2025
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 15365
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 81.060.30 Supersedes EN 15365:2010
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 grip method
Céramiques techniques avancées - Propriétés Hochleistungskeramik - Mechanische Eigenschaften
mécaniques des fibres céramiques à haute température von Keramikfasern bei hohen Temperaturen in einer
sous environnement non réactif - Détermination du reaktionsfreien Umgebung - Bestimmung des
comportement au fluage par la méthode des mors Kriechverhaltens im Kaltverbindungsverfahren
froids
This European Standard was approved by CEN on 24 November 2025.

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 CEN-CENELEC 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15365:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 7
5 Significance and use . 9
6 Apparatus . 9
6.1 Test installations . 9
6.2 Load train . 9
6.3 Test chamber . 9
6.4 Set-up for heating. 10
6.5 Temperature measurement . 10
6.6 Control of deformation . 10
6.7 Data recording system . 10
6.8 Determination of fibre cross-sectional area . 10
7 Test specimens . 10
7.1 Test specimen preparation . 10
7.2 Number of test specimens . 12
8 Test procedures . 12
8.1 Determination of the temperature profile in the furnace . 12
8.2 Test set-up: Determination of the temperature profile and of the different lengths of
each temperature zone in the furnace . 12
8.3 Test set-up: Loading considerations . 12
8.4 Test technique . 12
8.4.1 Specimen mounting . 12
8.4.2 Setting of an inert environment . 12
8.4.3 Heating of the test specimen . 13
8.4.4 Measurements . 13
8.4.5 Monitoring of temperature stability . 14
8.5 Test validity . 14
9 Calculation of results . 14
9.1 Creep stress . 14
9.2 Creep strain at time t . 15
9.2.1 Reading of the longitudinal deformation . 15
9.2.2 Calculation of the deformation due to the creep . 15
9.2.3 Drawing of the creep curve . 15
9.2.4 Creep strain at rupture . 15
9.2.5 Creep rupture time . 15
9.2.6 Creep strain rate curve . 15
10 Test report . 16
Bibliography . 17
European foreword
This document (EN 15365:2025) has been prepared by Technical Committee CEN/TC 184 “Advanced
technical ceramics”, the secretariat of which is held by DIN.
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 June 2026 and conflicting national standards shall be
withdrawn at the latest by June 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15365:2010.
a) the title was updated;
b) the normative references were updated;
c) the Bibliography was updated;
d) the document was editorially revised.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
1 Scope
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 is applicable 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 documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 (all parts), Thermocouples
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
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
Note 1 to entry: See 8.2.
3.4
specimen temperature in the zone
T
i
temperature defined as: T ≤ T ≤ T + i ΔT
t i t
3.5
total length
L
total length of the ceramic filament between the grips
3.6
length
L
i
length of the ceramic filament at temperature T
i
3.7
initial effective cross-sectional area
A
initial cross-sectional area of the ceramic filament within the gauge length
3.8
applied tensile force
F
constant force applied to the ceramic filament during the test
3.9
applied tensile stress
σ
applied tensile force divided by the initial cross-sectional area
3.10
longitudinal deformation
ΔL
change in the total length of the ceramic filament caused by creep
3.11
longitudinal deformation at temperature T
i
ΔL
i
change in the total length of the filament caused by creep at temperature T
i
3.12
tensile creep strain
ε
cr()T
relative change in length in the controlled zone at time t, caused by creep at the temperature T
Note 1 to entry: The value corresponding to rupture is denoted ε .
cr,m
3.13
creep rupture time
t
cr,m
time elapsed from the moment when loading is completed until the moment of rupture
3.14
creep strain rate

ε
cr()T
change in creep strain per unit time at time t at the temperature T
i
3.15
creep type
primary, secondary or tertiary creep
3.16
primary creep
part of the creep strain versus time curve which presents a decreasing creep strain rate
Note 1 to entry: See Figure 1.
3.17
secondary creep
part of the creep strain versus time curve which presents a constant creep strain rate
Note 1 to entry: See Figure 1.
3.18
tertiary creep
part of the creep strain versus time curve which presents an increasing creep strain rate
Note 1 to entry: See Figure 1.

a) Creep strain versus time
b) Creep strain rate versus time
Key
1 creep strain ε
cr
2 time t
3 primary creep
4 secondary creep
5 tertiary creep

6 creep strain rate (creep strain with time)
ε
cr
7 time t
8 primary creep
9 secondary creep
10 tertiary creep
Figure 1 — Creep strain and creep strain rate versus time curves
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 shall 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 (Figure 2).
Key
En entrance
Ex exit
L total length of the ceramic filament between the grips
P position (mm)
T temperature (°C)
l length of the furnace
Figure 2 — Temperature profile in furnace
If T is considered to be the lowest temperature at which creep is observed, the temperature profile can
t
be divided in several intervals as a function of T and ΔT, where ΔT is the difference in temperature
t
between the different zones, fixed by the operator.
Considering i, the entire number of zones, and L, the total fibre length, the following lengths are defined:
— L is the furnace length where the temperature T is in the range 20 °C ≤ T ≤ T ;
20 t
— L = L + 2L ;
0 2ΔT ΔT
— L is the furnace length where the temperature T is in the range T ≤ T ≤ T + ΔT;
ΔT t t
— L is the furnace length where the temperature T is in the range T + ΔT ≤ T ≤ T + 2 ΔT;
2ΔT t t
— L is the furnace length where the temperature T is in the range T + (i – 1) ΔT ≤ T ≤ T + i ΔT.
iΔT t t
Then L can be written:
L = L + L + L + L + … + L (1)
20 ΔT 2ΔT 3ΔT iΔT
Thus, it is possible to determine the deformation in all these different temperature zones. The true
deformation in the L zone requires the determination of the deformation in the lower temperature
2ΔT
zones. Below the temperature T and for a constant load applied to the fibre, the deformat
...