ISO 19630:2025

International
Standard
ISO 19630
Second edition
Fine ceramics (advanced ceramics,
2025-11
advanced technical ceramics) —
Methods of test for reinforcements
— Determination of tensile
properties of filaments at ambient
temperature
Céramiques techniques — Méthodes d’essai pour renforts
— Détermination des propriétés en traction des filaments à
température ambiante
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
4 Principle . 3
5 Apparatus . 3
6 Test specimen gauge lengths . 3
7 Test specimen preparation . 3
8 Number of test specimens . 4
9 Test procedure . 5
9.1 Displacement rate .5
9.2 Determination of the gauge length .5
9.3 Determination of the initial cross-section area .5
9.4 Testing technique .5
9.4.1 General .5
9.4.2 Load cell .5
9.4.3 Test specimen mounting .5
9.4.4 Measurements .5
9.4.5 Test validity .6
10 Calculation of results . 6
10.1 Tensile strength .6
10.1.1 Determination of maximum tensile force .6
10.1.2 Calculation of tensile strength .6
10.2 Calculation of the load train compliance,C .6
l
10.3 Strain .7
10.4 Young modulus .8
10.5 Fracture strain .8
11 Statistics . . 8
12 Test report . 9

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Foreword
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This document was prepared by Technical Committee ISO/TC 206, Fine ceramics, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 184, Advanced technical
ceramics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This second edition cancels and replaces the first edition (ISO 19630:2017) which has been technically
revised.
The main changes are as follows:
— Clause 3 updated;
— Clause 6 completely revised;
— Clause 8 updated;
— Clause 11 added;
— editorially revised.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
International Standard ISO 19630:2025(en)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods of test for reinforcements —
Determination of tensile properties of filaments at ambient
temperature
1 Scope
This document specifies the conditions for determination of the tensile properties of single filaments of
ceramic fibre such as the tensile strength, Young modulus and fracture strain.
This document applies to continuous ceramic filaments taken from tows, yarns, braids and knittings, which
have strain to fracture less than or equal to 5 %.
This document does not apply to carbon fibres that exhibit a nonlinear stress-strain curve. This document
does not apply to checking the homogeneity of strength properties of fibres, or to assessing the effects of
volume under stress. Methods of estimation of strength statistical parameters are indicated.
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.
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 19634, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ceramic composites — Notations
and symbols
ISO 20501, Fine ceramics (advanced ceramics, advanced technical ceramics) — Weibull statistics for strength data
EN 1007-3, Advanced technical ceramics — Ceramic composites — Methods of test for reinforcements — Part 3:
Determination of filament diameter and cross-section area
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in ISO 19634 and the following 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
gauge length
L
initial distance between two reference points on the filament
3.2
test specimen length
L
f
initial inner distance between the gripped ends of the filament

3.3
initial cross-section area
S
initial area of the cross section of the filament within the gauge length (3.1)
3.4
maximum tensile force
F
m
highest recorded force during a tensile test on the specimen when tested to failure
3.5
tensile stress
σ
ratio of the force carried by the test piece by the initial cross-section area (3.3)
3.6
tensile strength
σ
m
ratio of the maximum tensile force (3.4) to the initial cross-section area (3.3)
3.7
longitudinal deformation
A
increase of the gauge length caused by an applied load
3.8
total compliance
C
t
ratio of deformation to the corresponding force during the tensile test
3.9
load train compliance
C
l
ratio of the cross-head displacement excluding any test specimen contribution to the corresponding force
during the tensile test
3.10
strain
ε
ratio of longitudinal deformation (3.7) to gauge length (3.1) defined as the ratio A/L
3.11
fracture strain
ε
m
strain (3.10) at failure of the test specimen
3.12
Young modulus
E
slope of the linear part of the stress-strain curve when the linear part starts at the origin
3.13
elementary unit
smallest commercially available unit of a given product
Note 1 to entry: For fibre, this is usually a spool.

4 Principle
A ceramic filament is loaded in tension. The test is performed at constant displacement rate up to
failure. Force and cross-head displacement are measured and recorded simultaneously. The longitudinal
deformation is derived from the cross-head displacement using a compliance correction, when required.
5 Apparatus
5.1 Test machine, shall be equipped with a system for measuring the force applied to the test specimen
which shall conform to grade 1 in accordance with ISO 7500-1. Additionally, the machine shall be equipped
with a system for measuring the cross-head displacement with accuracy better than 1 µm.
5.2 Load train, in which the grips
...