EN ISO 18756:2005
(Main)Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of fracture toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method (ISO 18756:2003)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of fracture toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method (ISO 18756:2003)
ISO 18756:2003 describes a test method that covers the determination of fracture toughness of monolithic ceramic materials at room temperature by the surface crack in flexure (SCF) method.
This International Standard is intended for use with monolithic ceramics and whisker- or particulate-reinforced ceramics that are regarded as macroscopically homogeneous. It does not include continuous-fiber reinforced ceramic composites.
The test method is applicable to materials with either flat or rising crack growth resistance curves.
Hochleistungskeramik - Bestimmung der Bruchzähigkeit monolithischer Keramik bei Raumtemperatur für Biegeproben mit Oberflächenriss (Knoop-Riss) (SCF-Verfahren) (ISO 18756:2003)
Diese Internationale Norm legt ein Prüfverfahren zur Bestimmung der Bruchzähigkeit monolithischer keramischer Werkstoffe fest, das bei Raumtemperatur an Biegeproben mit Oberflächenriss (Knoop Riss) (SCF Verfahren) durchgeführt wird.
Diese Internationale Norm ist für die Anwendung auf monolithische Keramiken und durch Whisker oder Teilchen verstärkte Keramiken vorgesehen, die makroskopisch als homogen angesehen werden. Keramische Verbundstoffe mit Endlosfaserverstärkung werden nicht erfasst.
Das Prüfverfahren ist auf keramische Werkstoffe mit flachen oder ansteigenden Risswiderstandskurven (R Kurven) anwendbar. Es ist mit dem in ISO 15732 festgelegten Verfahren vergleichbar, allerdings sind die Anrisse kleiner und werden auf andere Weise erzeugt. Beide Verfahren sollten für Werkstoffe mit flacher Risswiderstandskurve ähnliche oder identische Ergebnisse liefern.
ANMERKUNG Das in dieser Norm festgelegte Prüfverfahren ist im Allgemeinen auf keramische Werkstoffe anwendbar, die eine Bruchzähigkeit von weniger als " 10 MPa×m1/2 haben. In Werkstoffen mit größerer Bruchzähigkeit oder in besonders weichen keramischen Werkstoffen (mit geringer Härte), z. B. einige Zirconiumoxide, oder auch in porösen keramischen Werkstoffen kann es schwierig sein, Anrisse mit einem Knoop Eindringkörper zu erzeugen.
Céramiques techniques - Détermination de la ténacité à la rupture des céramiques monolithiques à température ambiante par fissuration superficielle en flexion (ISO 18756:2003)
L'ISO 18756:2003 décrit une méthode d'essai qui couvre la détermination de la ténacité à la rupture de matériaux céramiques monolithiques, à température ambiante, par la méthode de fissuration superficielle en flexion (SCF).
L'ISO 18756:2003 est destinée à être utilisée avec des céramiques monolithiques et des céramiques à renfort de trichite ou de particules qui sont considérées comme homogènes d'un point de vue macroscopique. Elle ne couvre pas les composites céramiques à renfort de fibres continues.
La méthode d'essai est applicable aux matériaux ayant des courbes plates ou montantes de résistance à la propagation de la fissure.
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of fracture toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method (ISO 18756:2003)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2005
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination
of fracture toughness of monolithic ceramics at room temperature by the surface
crack in flexure (SCF) method (ISO 18756:2003)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of
fracture toughness of monolithic ceramics at room temperature by the surface crack in
flexure (SCF) method (ISO 18756:2003)
Hochleistungskeramik - Bestimmung der Bruchzähigkeit monolithischer Keramik bei
Raumtemperatur für Biegeproben mit Oberflächenriss (Knoop-Riss) (SCF-Verfahren)
(ISO 18756:2003)
Céramiques techniques - Détermination de la ténacité a la rupture des céramiques
monolithiques a température ambiante par fissuration superficielle en flexion (ISO
18756:2003)
Ta slovenski standard je istoveten z: EN ISO 18756:2005
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 ISO 18756
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2005
ICS 81.060.30
English Version
Fine ceramics (advanced ceramics, advanced technical
ceramics) - Determination of fracture toughness of monolithic
ceramics at room temperature by the surface crack in flexure
(SCF) method (ISO 18756:2003)
Céramiques techniques - Détermination de la ténacité à la Hochleistungskeramik - Bestimmung der Bruchzähigkeit
rupture des céramiques monolithiques à température monolithischer Keramik bei Raumtemperatur für
ambiante par fissuration superficielle en flexion (ISO Biegeproben mit Oberflächenriss (Knoop-Riss) (SCF-
18756:2003) Verfahren) (ISO 18756:2003)
This European Standard was approved by CEN on 2 June 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.
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© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18756:2005: E
worldwide for CEN national Members.
Foreword
The text of ISO 18756:2003 has been prepared by Technical Committee ISO/TC 206 "Fine
ceramics" of the International Organization for Standardization (ISO) and has been taken over as
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 January 2006, and conflicting national
standards shall be withdrawn at the latest by January 2006.
This document is part of a series:
CEN/TS 14425-1 Advanced technical ceramics — Test methods for determination of fracture
toughness of monolithic ceramics — Part 1: Guide to test method selection
CEN/TS 14425-3 Advanced technical ceramics — Test methods for determination of fracture
toughness of monolithic ceramics — Part 3: Chevron notched beam (CNB) method
CEN/TS 14425-5 Advanced technical ceramics — Test methods for determination of fracture
toughness of monolithic ceramics — Part 5: Single-edge V-notch beam (SEVNB) method
EN ISO 15732 Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method
for fracture toughness of monolithic ceramics at room temperature by single edge precracked
beam (SEPB) method
EN ISO 18756 Fine ceramics (advanced ceramics, advanced technical ceramics) —
Determination of fracture toughness of monolithic ceramics at room temperature by the surface
crack in flexure (SCF) method
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.
Endorsement notice
The text of ISO 18756:2003 has been approved by CEN as EN ISO 18756:2005 without any
modifications.
INTERNATIONAL ISO
STANDARD 18756
First edition
2003-12-01
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Determination of fracture toughness of
monolithic ceramics at room temperature
by the surface crack in flexure (SCF)
method
Céramiques techniques — Détermination de la ténacité à la rupture des
céramiques monolithiques à température ambiante par fissuration
superficielle en flexion
Reference number
ISO 18756:2003(E)
©
ISO 2003
ISO 18756:2003(E)
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ii © ISO 2003 — All rights reserved
ISO 18756:2003(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 3
5 Principle . 4
6 Apparatus. 5
7 Test specimens . 6
7.1 Specimen size, preparation and edge chamfering . 6
7.2 Number of specimens. 6
8 Procedure. 7
8.1 Introduction of the precrack by Knoop indentation . 7
8.2 Specimen fracture. 11
8.3 Crack size measurement. 12
8.4 Environmental effects. 13
8.5 Optional: Estimate of R-curve behaviour .14
8.6 Optional: Reference materials . 14
9 Calculation. 14
10 Test report. 15
Annex A (informative) Environmental effects. 17
Annex B (normative) Precrack characterization . 18
Annex C (informative) R-curve estimation by the SCF method. 25
Annex D (normative) Chamfer correction factors. 27
Bibliography . 29
ISO 18756:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18756 was prepared by Technical Committee ISO/TC 206, Fine ceramics.
iv © ISO 2003 — All rights reserved
INTERNATIONAL STANDARD ISO 18756:2003(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Determination of fracture toughness of monolithic
ceramics at room temperature by the surface crack in flexure
(SCF) method
1 Scope
This International Standard describes a test method that covers the determination of fracture toughness of
monolithic ceramic materials at room temperature by the surface crack in flexure (SCF) method.
This International Standard is intended for use with monolithic ceramics and whisker- or particulate-reinforced
ceramics that are regarded as macroscopically homogeneous. It does not include continuous-fibre reinforced
ceramic composites.
The test method is applicable to materials with either flat or rising crack growth resistance curves. This
method is similar to ISO 15732 except that precracks are smaller and are made by a different procedure. The
methods should produce similar or identical results for materials with a flat R-curve.
1/2
NOTE This test method is usually applicable to ceramic materials with a fracture toughness less than ≈ 10 MPa m . It
may be difficult to form precracks with a Knoop indenter for materials with greater fracture toughness or those materials
which are soft (low hardness) such as some zirconias, or for porous ceramics.
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.
ISO 3611:1978, Micrometer callipers for external measurement
1)
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 14704:2000, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural
strength of monolithic ceramics at room temperature
3 Terms and definitions
For the purposes of this document, the following
...
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