SIST EN ISO 2738:2000

SLOVENSKI STANDARD
01-december-2000
Sintered metal materials, excluding hardmetals - Permeable sintered metal
materials - Determination of density, oil content and open porosity (ISO 2738:1999)
Sintered metal materials, excluding hardmetals - Permeable sintered metal materials -
Determination of density, oil content and open porosity (ISO 2738:1999)
Matériaux métalliques frittés, a l'exclusion des métaux durs - Matériaux métalliques
frittés perméables - Détermination de la masse volumique, de la teneur en huile et de la
porosité ouverte (ISO 2738:1999)
Ta slovenski standard je istoveten z: EN ISO 2738:1999
ICS:
77.160 Metalurgija prahov Powder metallurgy
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 2738
Third edition
1999-11-01
Sintered metal materials, excluding
hardmetals — Permeable sintered metal
materials — Determination of density, oil
content and open porosity
Matériaux métalliques frittés, à l'exclusion des métaux-durs — Matériaux
métalliques frittés perméables — Détermination de la masse volumique, de
la teneur en huile et de la porosité ouverte
A
Reference number
ISO 2738:1999(E)
ISO 2738:1999(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 3.
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.
International Standard ISO 2738 was prepared by Technical Committee ISO/TC 119, Powder metallurgy,
Subcommittee SC 3, Sampling and testing methods for sintered metal materials (excluding hardmetals).
This third edition cancels and replaces the second edition (ISO 2738:1987) which has been technically revised.
©  ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii
INTERNATIONAL STANDARD  © ISO ISO 2738:1999(E)
Sintered metal materials, excluding hardmetals — Permeable
sintered metal materials — Determination of density, oil content
and open porosity
1 Scope
This international Standard specifies methods of determining the density, oil content and open porosity of
permeable sintered metal materials.
It applies in particular to porous metal bearings and to structural parts produced by pressing and sintering metal
powders.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 758, Liquid chemical products for industrial use — Determination of density at 20 °C.
ISO 13944, Lubricated metal-powder mixes — Determination of lubricant content — Modified Soxhlet extraction
method.
© ISO
ISO 2738:1999(E)
3 Symbols and designations
Table 1 — Symbols and designations
Symbol Designation Unit
m Initial mass of the test piece g
m Mass of the test piece after oil extraction and drying g
Mass of the fully impregnated test piece g
m
m Mass of the fully or partially impregnated test piece plus supporting device (for g
a
example suspension wire) weighed in air
m Mass of the fully or partially impregnated test piece plus supporting device (for g
w
example suspension wire) weighed in water
V Volume of the test piece cm
r Density of the water used g/cm
w
r a
g/cm
1 Density of the oil initially in the test piece
r a
g/cm
2 Density of the impregnating oil used
a
The oil density is assumed to be known or, if not, to be determined in accordance with ISO 758.
4 Terms and definitions
For the purposes of this International Standard the following terms and definitions apply.
4.1
density
the density of the test piece may be expressed in two ways:
4.1.1
dry density
the mass, after drying, divided by the volume
4.1.2
fully impregnated density (wet density)
the fully impregnated mass divided by the volume
4.2
oil content
the oil content of the test piece may be expressed in two ways:
4.2.1
percentage by volume
the volume of the oil divided by the volume of the test piece and multiplied by 100
4.2.2
percentage of the volume of the open porosity
the volume of the oil divided by the volume of the open porosity and multiplied by 100
4.3
open porosity (of the test piece)
the oil content after full impregnation divided by the volume of the test piece and multiplied by 100 expressed as a
percentage by volume
4.4
volume (of the test piece)
total volume including the pores
© ISO
ISO 2738:1999(E)
5 Test procedures
Depending upon which of the properties is to be determined, some or all of the test procedures in clause 8 are
carried out. Table 2 shows the test procedures that are carried out for the property to be determined. The values
obtained for the various parameters are inserted in the respective formulae given in clause 9 to obtain the desired
property.
Table 2 — Test procedures
Test procedure Symbol for Properties to be determined
result
obtained
Density Oil content Open
porosity
Dry Fully % (V/V) % of
impregnated open
porosity
Initial weighing of the test piece (see 8.1) m 33
Extraction of the oil contained in the pores of the 3333
test piece (see 8.2)
Determination of the mass of the test piece after m3333
oil extraction and drying (see 8.3)
Full impregnation of the test piece with an oil of 333
known density (see 8.4)
Determination of the mass of the fully m 333
impregnated test piece (see 8.5)
Determination of the volume of the test piece V 33 3 3
(see 8.6)
6 Equipment
6.1 Analytical balance, of sufficient capacity and accurate to 0,01 %.
6.2 Soxhlet extractor, with oil solvent.
6.3 Device for weighing the test piece in air and in liquid
NOTE The liquid is usually water (see Figures 1, 2 and 3).
6.4 Vessel, large enough to accommodate the test piece and the device (6.3) for weighing it, containing distilled or
deionized, and preferably degassed water, with 0,05 % (V/V) to 0,10 % (V/V) wetting agent added.
6.5 Apparatus for vacuum impregnation of the test piece with oil
6.6 Impregnation oil, of known density (see ISO 758 for the determination of the density of liquids).
6.7 Thermometer, accurate to ± 0,5 °C.
© ISO
ISO 2738:1999(E)
7 Test piece
7.1  Usually the test piece is tested whole. If this is not possible, the test piece may be cut or broken into smaller
parts to facilitate the various operations. It is often most appropriate to test only a critical section of a component.
If the test piece has a mass less than 5 g a number of test pieces shall be tested together to obtain the
7.2
average value.
7.3  The surface of the test piece shall be free of adhering dirt, grease or other foreign material.
7.4  The surface of the test piece shall be free from surplus oil. When removing any such surplus oil with an oil-
absorbent material, care shall be taken to avoid removing oil contained in the pores.
NOTE The presence of surplus oil on the surface of the test piece is most likely to occur after the full impregnation
treatment.
8 Test procedures
8.1 Determination of the initial mass of the test piece
Weigh the test piece in the condition in which it was received, to obtain m .
NOTE If the test piece is known to contain no oil, the procedures described in 8.2 and 8.3 are omitted. In this case, m is
substituted for m in the formulae given in 9.1 and 9.3.
8.2 Removal of oil from the test piece by solvent extraction
Approximately 3 h of soaking and about ten solvent changes are required to remove the oil from test pieces of
average density and small wall thickness. For thick walls and high density, up to 24 h are sometimes required.
NOTE 1 The Soxhlet extractor is a convenient apparatus for soaking the test piece in warm, freshly distilled oil solvent. The
distillation rate determines the number of cycles and hence the number of solvent changes that occur. A suitable Soxhlet unit is
d
...