Bsi bs en 00623 2 1993 (1999)

www bzfxw com BRITISH STANDARD BS EN 623 2 1993 Advanced technical ceramics — Monolithic ceramics — General and textural properties — Part 2 Determination of density and porosity The European Standard[.]

BRITISH STANDARD BS EN

623-2:1993

Advanced technical

ceramics —

Monolithic ceramics —

General and textural

properties —

Part 2: Determination of density and

porosity

The European Standard EN 623-2:1993 has the status of a

British Standard

UDC 666.5/.6:620-1:531.75

This British Standard, having

been prepared under the

direction of the Refractory

Products Standards Policy

Committee, was published

under the authority of the

Standards Board and comes

into effect on

15 November 1993

© BSI 10-1999

The following BSI references

relate to the work on this

standard:

Committee reference RPM/13

Draft for comment 92/36001 DC

ISBN 0 580 21772 8

Cooperating organizations

The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries:

Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y

France Association française de normalisation Germany Deutsches Institut für Normung e.V

Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland

Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portuguès da Qualidade Spain Asociación Española de Normalización y Certificación Sweden Standardiseringskommissionen i Sverige

Switzerland Association suisse de normalisation United Kingdom British Standards Institution

Amendments issued since publication

BS EN 623-2:1993

Contents

Page

National annex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-references Inside back cover

ii © BSI 10-1999

National foreword

This British Standard has been prepared under the direction of the Refractory Products Standards Policy Committee and is the English language version of

EN 623-2 Advanced technical ceramics — Monolithic ceramics — General and

textural properties — Part 2: Determination of density and porosity published by

the European Committee for Standardization (CEN) It supersedes

BS 7134-1.2:1989 which is withdrawn

EN 623-2 was produced as a result of international discussions in which the UK took an active part

A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover

This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 623-2

September 1993

UDC 666.5/.6:620.1:531.75

Descriptors: Ceramics, characteristics, tests, determination, bulk density, porosity, quality

English version

Advanced technical ceramics — Monolithic ceramics —

General and textural properties — Part 2: Determination of density and porosity

Céramiques techniques avancées —

Céramiques monolithiques — Propriétés

générales et structurales — Partie 2:

Détermination de la masse volumique et de la

porosité

Hochleistungskeramik — Monolithische Keramik — Allgemeine und strukturelle Eigenschaften — Teil 2: Bestimmung von Dichte und Porosität

This European Standard was approved by CEN on 1993-08-30 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,

Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,

Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and

United Kingdom

CEN

European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

© 1993 Copyright reserved to CEN members

Ref No EN 623-2:1993 E

© BSI 10-1999 2

Foreword

This European Standard has been prepared by

Technical Committee CEN/TC 184 “Advanced

technical ceramics” the secretariat of which is held

by BSI

EN 623 Advanced technical ceramics — Monolithic

ceramics — General and textural properties consists

of four Parts:

— Part 1: Determination of the presence of defects

by dye penetration tests;

— Part 2: Determination of density and porosity;

— Part 3: Determination of grain size1);

— Part 4: Determination of surface roughness1)

The 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

March 1994, and conflicting national standards

shall be withdrawn at the latest by March 1994

In accordance with the CEN/CENELEC Internal

Regulations, the following countries are bound to

implement this European Standard: Austria,

Belgium, Denmark, Finland, France, Germany,

Greece, Iceland, Ireland, Italy, Luxembourg,

Netherlands, Norway, Portugal, Spain, Sweden,

Switzerland and United Kingdom

Contents

Page

4 Statement of accuracy and errors 3

5 The evacuation method (Method 1) 4

6 Method by measurement of dimensions and mass (geometric

Table 1 — Accuracy and errors of density and porosity measurement 4 Table 2 — Density of distilled water

as a function of temperature

1) Parts 3 and 4 of this European Standard will be published as ENV.

EN 623-2:1993

1 Scope

This Part of EN 623 describes methods for

determination of the bulk density, apparent solid

density, and apparent porosity of advanced

technical ceramics

Two methods are described and are designated as

Methods 1 and 2, as follows

Method 1 Determination of bulk density,

apparent solid density and apparent porosity by

the evacuation method

NOTE 1 This method is not suitable for the determination of

apparent porosity of less than 1 % A method for determining

the presence of defects and surface porosity in this type of

material is given in EN 623-1.

NOTE 2 The method is also not suitable for materials which

are known to have an average pore size of greater

than 200 Èm.

Method 2 Determination of bulk density only, by

measurement of dimensions and mass

NOTE 3 Neither of these test methods measures total

porosity including open and closed pores This parameter may

be calculated from the test results of Method 1 if the true

density of pore-free material is known.

2 Normative references

This European Standard incorporates by dated or

undated reference, provisions from other

publications These normative references are cited

at the appropriate places in the text and the

publications are listed hereafter For dated

references, subsequent amendments to or revisions

of any of these publications apply to this European

Standard only when incorporated in it by

amendment or revision For undated references the

latest edition of the publication referred to applies

EN 623-1, Advanced technical ceramics —

Monolithic ceramics — General and textural

properties — Part 1: Determination of the presence of

defects by dye penetration tests

EN 45001, General criteria for the operation of

testing laboratories

EN 1006, Advanced technical ceramics — Methods

of testing monolithic ceramics — Guidance on the

sampling and selection of test pieces

ISO 758:1976, Liquid chemical products for

industrial use — Determination of density at 20 °C

ISO 3611:1978, Micrometer callipers for external

measurement

ISO 4964:1984, Steel — Hardness conversions

ISO 6906:1984, Vernier callipers reading

to 0,02 mm

3 Definitions

For the purposes of this Part of EN 623 the following definitions apply

3.1 open pores

pores that are penetrated by an immersion liquid in vacuum, or that are connected with the atmosphere, either directly or via one another

3.2 closed pores

pores that are not penetrated by the immersion liquid, or that are not connected with the atmosphere

3.3

bulk volume Vb

the sum of the volumes of the solid material, the open pores and the closed pores in a porous body

3.4 true volume

the volume of a body occupied by solid material, excluding all forms of porosity

3.5

apparent solid volume Vs

the sum of the volume of the closed pores and true volume

3.6 bulk density Ôb

the ratio of the mass of the dry material of a porous body to its bulk volume

3.7 geometric bulk density

the mass per unit total volume of a material including all porosity accessible and in accessible from the surface, the volume being calculated from linear dimensions

3.8 apparent solid density Ôs

the ratio of the mass of the dry material to its apparent solid volume

3.9 apparent porosity Ï a

the ratio of the total volume of the open pores in a porous body to its bulk volume

4 Statement of accuracy and errors

The minimum accuracy of measurement of the parameters used in calculation of densities and porosities is given in Table 1

Table 1 — Accuracy and errors of density and porosity measurement

5 The evacuation method (Method 1)

5.1 Principle

The mass of dry test piece is determined by

weighing, then its apparent mass when immersed in

a liquid with which it has been impregnated under

vacuum, and then its mass in air while still soaked

with the liquid From these values its bulk density

and apparent porosity are determined by

calculation

5.2 Apparatus

5.2.1 Drying oven, capable of maintaining a

temperature of 110 °C ± 5 °C

5.2.2 Balance with accuracy in accordance with

clause 4.

5.2.3 A bridge, to be placed over the load-bearing

scale pan of the balance (see 5.2.2), if the balance is

not equipped for suspension loading

5.2.4 Evacuating equipment, capable of reducing the

pressure to a value less than 2 500 Pa (25 mbar),

and a means of measuring the pressure used

NOTE If a rotary vacuum pump is used, it should be fitted with

a moisture trap, to minimize the mixing of water and the pump

lubrication system.

5.2.5 Degreased metal wire, of diameter not more

than 0,15 mm

5.2.6 Cradle to contain test piece(s) (optional).

5.2.7 Immersion liquid, which may be either:

a) cold distilled water, containing a dilute

solution of a surface active agent (concentration

not more than 0,01 %), the addition of which does

not change the densities given in Table 2; or

b) an organic liquid, which shall be used for

materials that are sensitive to contact with water

or that cannot be fully wetted by water

NOTE Some materials may chemically react with water, others such as boron nitride are not wetted by water Where test pieces

of smaller volume (1 cm 3 to 10 cm 3) (see 5.3.1) are used, and the

error caused by evaporation of liquids is comparatively high, dibutyl phthalate should be used.

5.2.8 Thermometer, capable of measuring to ± 0,1 K.

5.2.9 Glass beaker, of a size allowing adequate

clearance of its walls by the test piece

5.2.10 Desiccator, for storage of test pieces.

5.2.11 Manometer 5.2.12 Absorbent cloth or tissue paper

5.3 Test pieces 5.3.1 Materials for testing shall be sampled in accordance with the guidance given in ENV 1006

Test pieces shall be either whole or broken ceramic products, or shall be cut from blocks or rods of the same material The bulk volume of a test piece shall

be not less than 1 cm3, and its mass shall be greater than 1 g (see Table 1 and note 2)

NOTE 1 When the apparent porosity is greater than 10 %, the ratio of the longest to the shortest dimension of a test piece should not exceed 2 : 1.

NOTE 2 For test pieces of mass 1 g to 3 g, significant sources of error include temperature, air content of liquid and the consistency of the liquid level position on the suspension wire

These factors should be kept constant.

5.3.2 If any surface treatment such as the removal

of “skin” is carried out this shall be reported in the

test report (see clause 7).

NOTE Since it is necessary to sponge the surface of the test piece to remove surface moisture, the test pieces should not have inaccessible external surfaces or very rough surfaces.

5.4 Procedure 5.4.1 Determination of the mass of the dry test piece

Dry the test piece in the oven (see 5.2.1)

at 110 °C ± 5 °C to constant mass, i.e until two successive weighings made before and after at least 2 h in the drying oven do not differ by more than 0,03 %

Method 1:

Evacuation method

(see clause 5)

Method 2:

Geometric bulk density

(see clause 6)

Accuracy of measurement of

dimensiona

dimension

Accuracy of measurement of density of

immersion liquid, (Mg/m3);

see 5.5 and Table 2

a The maximum non-uniformity of any dimension should not exceed 1 % of its average value.

EN 623-2:1993

Before each weighing, place the test piece in the

desiccator (see 5.2.10), until it has cooled to room

temperature, and weigh it as quickly as possible

after removal from the desiccator The mass thus

determined is the mass of the dry test piece (m1),

weighed in accordance with Table 1

5.4.2 Soaking of test piece

Place the cooled and dried test piece in an airtight

vessel Seal the vessel and evacuate it until a

pressure of less than 2 500 Pa is attained; maintain

this vacuum for at least 15 min In order to ensure

that all the air has been removed from the test piece,

isolate or disconnect the vessel from the vacuum

pump and use the manometer (see 5.2.11) to check

that the pressure does not rise through any

degassing of the test piece Progressively introduce

the immersion liquid in such a way that,

after 3 min, the test piece is covered by

about 20 mm of liquid Reconnect the vessel to the

vacuum pump and maintain this reduced pressure

for 30 min, then switch off the pump and open the

vessel to ambient air pressure Wait for at least a

further 30 min to ensure complete penetration of

the test piece by the liquid

NOTE If there is any doubt about the completion of penetration

within 30 min, this period may be extended by agreement

between parties as required.

5.4.3 Determination of the apparent mass of the

immersed test piece

Suspend the test piece by the thin wire (see 5.2.5)

from the load-pan suspension point of the balance,

perpendicular to the liquid, and weigh it while

completely immersed in a quantity of the immersion

liquid, contained in the beaker (see 5.2.9), standing

on the bridge (see 5.2.3) if used Remove bubbles

from the surface of the test piece and weigh Remove

the test piece from the suspension wire, replace the

wire in the liquid to the same suspension level and

weigh The difference between the two weighings is

the apparent mass of the immersed test piece (m2),

weighed in accordance with Table 1 Determine the

temperature of the immersion liquid, using the

thermometer (see 5.2.8).

5.4.4 Determination of the mass of the soaked

test piece

Remove the test piece from the liquid and, without

waiting, sponge it quickly and carefully with a

damp, lint-free absorbent cloth or tissue (see 5.2.12)

to remove droplets and the surface film of liquid, but

avoid drawing out liquid from the pores of the test

piece

Immediately weigh the test piece in air Take care to

ensure that evaporation of the immersion liquid

does not lead to any appreciable loss in mass during

the weighing operation

NOTE If such loss occurs, the test should be repeated using a

different immersion liquid (see note to 5.2.7).

Record the mass thus determined as the mass of the

soaked test piece (m3), weighed in accordance with Table 1 Repeat the immersion, drying and

weighing

If the results for each test piece differ by more than the relevant accuracy figures given in Table 1, repeat the test until two sets of figures meet these criteria

5.5 Determination of the density of the immersion liquid

Determine the density of the liquid used in the operation at the temperature of the test, using the method given in ISO 758:1976, to the accuracy given

in Table 1

NOTE 1 For distilled water, the density at various temperatures is given in Table 2.

NOTE 2 As many organic solvents have high coefficients of volume thermal expansion, the determination of density of the liquid should be carried out at the same temperature as that of the measurement of the apparent mass of the immersed test

piece (see 5.4.3)

Table 2 — Density of distilled water as a function of temperature between 15 °C

and 30 °C

5.6 Calculation of results 5.6.1 Calculate the bulk density Ôb, in either megagrams per cubic metre or kilograms per cubic metre from the following equation:

Temperature, °C Density, Ô

Mg/m 3 Kg/m 3

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

0,99910 0,99894 0,99877 0,99860 0,99841 0,99820 0,99799 0,99777 0,99754 0,99730 0,99704 0,99678 0,99651 0,99623 0,99594 0,99565

999,10 998,94 998,77 998,60 998,41 998,20 997,99 997,77 997,54 997,30 997,04 996,78 996,51 996,23 995,94 995,65

(1)

5.6.2 Calculate the apparent solid density Ôs, in

either megagrams per cubic metre or kilograms per

cubic metre

5.6.3 Calculate the apparent porosity Ïa as a

percentage, (V/V) from the following equation:

where:

m1 is the mass of the dry test piece in grams

(see 5.4.1);

m2 is the apparent mass of the immersed test

piece in grams (see 5.4.3);

m3 is the mass of the soaked test piece in grams

(see 5.4.4);

ÔL is the density of the immersion liquid (see 5.5)

in megagrams per cubic metre or kilograms per

cubic metre, as appropriate to the units chosen

for the calculation

Express the values of density in megagrams per

cubic metre or kilograms per cubic metre to three

significant digits

Express the values of porosity to the nearest 0,1 %

6 Method by measurement of

dimensions and mass (geometric bulk

density) (Method 2)

6.1 Principle

A test piece of uniform geometry within specified

tolerances is dried and weighed Its volume is

determined by measurement of the appropriate

dimensions The geometric bulk density (see 3.7) is

calculated as mass per unit volume

6.2 Apparatus

6.2.1 Balance, with accuracy in accordance with

Table 1

6.2.2 Calibrated measuring device capable of

repeatable and accurate measurement in

accordance with Table 1, e.g vernier callipers in

accordance with ISO 6906:1984, or a micrometer in

accordance with ISO 3611:1978

NOTE For flat test piece surfaces, spherical measuring anvils

with radii of curvature between 2 mm and 10 mm should be

used For cylindrical test piece surfaces, cylindrical measuring

anvils should be used These anvils should be constructed of

material with hardness of at least 500 HV30

(see ISO 4964:1984).

6.2.3 Drying oven, capable of maintaining a

temperature of 110 °C ± 5 °C

6.2.4 Desiccator, for storage of test pieces.

6.3 Test pieces

Materials for testing shall be sampled in accordance with the guidance given in ENV 1006 The shape of test pieces shall be such that the volume can be calculated from the external dimensions

NOTE 1 Ideal shapes are rectangular parallelepipeds and right cylinders, discs or rods.

NOTE 2 Test pieces which do not have uniform dimensions and principal axes orthogonal to within 1° should be ground to achieve such conditions.

The mass of the test piece shall be greater than 2 g and each dimension shall be greater than 3 mm (see Table 1) Where “as-fired” test pieces are used, press flashing shall be removed

NOTE 3 The total volume of edge chips and surface pits or protrusions should not exceed approximately 0,1 % of the nominal total volume.

NOTE 4 Some types of material possess surface skins which are rough or soft in the “as-fired” state These materials are unsuited

to this method of measurement of bulk density unless the skin is flattened or removed by machining or other suitable method

Reaction-bonded silicon nitride is an example where such a surface deposit may be present.

6.4 Procedure

Dry the test pieces in the oven (see 6.2.3)

at 110 °C ± 5 °C to constant mass, i.e until two successive weighings made before and after at least 2 h in the drying oven do not differ by more than 0,03 % Transfer them to a desiccator and allow to cool to room temperature Record the mass

of each test piece in ambient air, as soon as possible after removal from the desiccator

Using the selected measuring device (see 6.2.2),

measure the dimensions of each test piece at at least three positions for each direction, to an accuracy better than 0,01 mm or 0,05 % of the smallest dimension Measure the directions parallel to the principal geometric axes, e.g the length, breadth and depth of a parallelepiped, the length and diameter for a disc or a rod

NOTE If the dimensions of the test piece are too small to make three separate measurements in any direction, e.g of the length

of a rod of small diameter, a single measurement may be used,

such a simplified procedure being reported [see clause 7j)].

Calculate the differences between the lowest and highest figures measured for each direction Reject the test pieces if any difference exceeds 1 % of the mean dimensions measured

6.5 Results

Calculate the geometric volume of each test piece from its mean dimensions The geometric bulk density is given by the mass divided by the geometrical volume Express the values of density in megagrams per cubic metre or kilograms per cubic metre

(2)

(3)