1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 14168:2011Metallic powders, excludinghardmetals Method fortesting copper-base infiltratingpowdersBS ISO 14168:2011 BRITISH STANDARDNational forewordThis British Standard i
2、s the UK implementation of ISO 14168:2011. Itsupersedes BS ISO 14168:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/65, Sintered metal components.A list of organizations represented on this committee can beobtained on request to its secretary.
3、This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72071 0ICS 77.160Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under
4、the authority of theStandards Policy and Strategy Committee on 31 December 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 14168:2011Metallic powders, excluding hardmetals Method for testing copper-base infiltrating powdersPoudres mtalliques, lexclusion des mtaux-durs Mtho
5、de dessai des poudres infiltrantes base cuivre ISO 2011Reference numberISO 14168:2011(E)Second edition2011-11-15ISO14168INTERNATIONAL STANDARDBS ISO 14168:2011ISO 14168:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, no part of this publication may be rep
6、roduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 74
7、9 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2011 All rights reservedBS ISO 14168:2011ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing
8、 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 liais
9、on 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 tech
10、nical 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
11、 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 14168 was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee SC 2, Sampling and testing met
12、hods for powders (including powders for hardmetals).This second edition cancels and replaces the first edition (ISO 14168:2003), of which it constitutes a minor revision.ISO 14168:2011(E) ISO 2011 All rights reserved iiiBS ISO 14168:2011IntroductionSintered materials generally have a porous structur
13、e. There is, however, one group of metallic materials in which the porosity is greatly reduced by filling the open pores with lower-melting-point alloys, a process made possible by the capillary action of the pores. This group of materials is called infiltrated materials.In most cases, this process
14、is carried out as the infiltration of copper or copper-base alloys into higher-melting-point skeletons.ISO 14168:2011(E)iv ISO 2011 All rights reservedBS ISO 14168:2011INTERNATIONAL STANDARD ISO 14168:2011(E)Metallic powders, excluding hardmetals Method for testing copper-base infiltrating powders1
15、ScopeThis International Standard specifies a method for determining the performance characteristics of copper-base infiltrating powders.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applie
16、s. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2738, Sintered metal materials, excluding hardmetals Permeable sintered metal materials Determination of density, oil content and open porosityISO 3325, Sintered metal materials, excluding
17、 hardmetals Determination of transverse rupture strengthISO 3927, Metallic powders, excluding powders for hardmetals Determination of compressibility in uniaxial compressionISO 3995, Metallic powders Determination of green strength by transverse rupture of rectangular compactsISO 4492, Metallic powd
18、ers, excluding powders for hardmetals Determination of dimensional changes associated with compacting and sinteringISO 4498, Sintered metal materials, excluding hardmetals Determination of apparent hardness and microhardness3 PrincipleThe infiltrant is placed in contact with a skeleton, usually of i
19、ron-base composition, and both components are heated above the melting point of the infiltrant.The infiltration efficiency and loose residue are calculated.4 Apparatus4.1 Compression testing machine or hydraulic powder press, capable of applying the required pressure.4.2 Compacting tools, for produc
20、ing the required specimens and infiltrant compacts.4.3 Furnace, muffle type or equivalent, having a heating chamber capable of maintaining a temperature of 1 120 C 8 C; it shall have a reducing atmosphere in the hot zone while maintaining a non-oxidizing atmosphere in the cooling chamber.4.4 Balance
21、, suitable for weighing accurately to within 0,01 g.4.5 Micrometers, capable of measuring to 0,005 mm. ISO 2011 All rights reserved 1BS ISO 14168:20115 Test specimens5.1 To test an infiltrating powder, the preferred skeleton to be infiltrated is 25 mm diameter by 12,7 mm height (see ISO 3927). The s
22、keleton may be infiltrated simultaneously with sintering, or in a separate step after sintering. The use of a one-step or two-step infiltration shall be a matter of agreement between parties, since final part properties depend on the infiltration steps.The composition of the skeletons, including the
23、 type of material and the green density, shall also be a matter of agreement between the parties concerned. The uniformity of the skeletons may be determined by measuring the mass. The mass shall not vary from the mean by more than 0,5 %.5.2 The recommended infiltrant compact is a cylinder nominally
24、 12,7 mm in diameter compacted from a copper or copper-base infiltrant mix. Normally the infiltrant mix shall also contain a dry lubricant. The composition of the infiltrant, including the type of lubricant and the mass and green density of the infiltrant compact, shall be a matter of agreement betw
25、een the parties concerned. The uniformity of the infiltrant compacts shall be determined by weighing. The mass of any compact shall not vary by more than 0,5 % from the mean.5.3 The recommended infiltrant compact, when placed on the skeleton, has a contact area of 126,5 mm2. Since the infiltrant loa
26、ding mass per unit contact area can affect the test results, this shall be a matter of agreement between the parties and shall be reported in the test report.5.4 An alternative specimen is the transverse rupture bar described in ISO 3995, ISO 4492 and ISO 3325. The advantage of using this specimen i
27、s that the transverse rupture strength can be measured, as well as the infiltrant efficiency.5.5 Alternatively, skeleton specimens may be made of any iron-base structural piece, of composition and sintered or green density that are acceptable to the parties concerned. Likewise, the infiltrant compac
28、t may be any available shape that is acceptable to the parties concerned, with composition, lubricant, mass and green density a matter for agreement between the parties concerned. The mass of the skeleton and infiltrant compact shall not vary by more than 0,5 % from the mean.6 Procedure6.1 Weigh the
29、 skeleton specimens and accurately measure the dimensions. Three specimens for each infiltrant being evaluated shall be prepared.The density of the skeleton is determined either by calculation from the mass and dimensions or by weighing in air and water as described in ISO 2738. If the method of ISO
30、 2738 is used to determine the density, do not use any specimen that was used for water displacement density testing for subsequent infiltration. In this case, three additional specimens shall be made for the density measurement. These three specimens shall be made of the same powder mix and accordi
31、ng to the same procedure as the skeleton specimens to be used for the infiltration. The reported density of the skeleton specimens shall be the calculated mean value of the three specimens.The skeletons are placed on a suitable tray or container for transporting the specimens through the infiltratin
32、g furnace. The type of tray or container shall be agreed upon by the interested parties. Care shall be taken to avoid contact with materials that would react with the skeleton or the infiltrant. The skeletons are normally positioned with one punch face surface facing up.6.2 The weighed infiltrant co
33、mpact shall be approximately centred on the upward-facing punch face surface. The symbol for this mass is m1. The use of a small amount of sticky sucrose solution or other adhesive between ISO 14168:2011(E)2 ISO 2011 All rights reservedBS ISO 14168:2011the two parts, or some other method of keeping
34、the infiltrant compact in place, shall be a matter of agreement between the parties concerned. The specimens shall not touch each other but shall be spaced well apart.A reference infiltrating powder, which has been agreed upon by the parties concerned, shall be run at the same time as the infiltrant
35、 under test. Comparison between the reference and the tested infiltrant serves to verify that the test conditions, particularly furnace conditions and atmosphere, are not abnormal.Extra skeleton specimens shall also be run through the infiltrating furnace cycle without an infiltrant compact in conta
36、ct. After the furnace treatment, the mass of these extra specimens shall be determined (m2). This value represents the mass of the original skeleton adjusted for the mass loss in the furnace treatment resulting from the reducible oxides, decarburization, loss of other volatiles, and the volatilizati
37、on of lubricants when green skeleton specimens are used.6.3 Specific infiltration conditions shall be a matter of agreement between the parties concerned. It is suggested that the following infiltration data be determined and recorded: heat-up time and rate, cooling time and rate, time at temperatur
38、e; range of furnace temperatures during infiltration; furnace atmosphere, including moisture content at inlet to furnace or sampled from the hot zone, and the rate of flow with respect to the cross-section of the furnace hearth.6.4 Observe and note the appearance of the infiltrated specimens as each
39、 tray is removed from the furnace.Weigh each infiltrated specimen plus any residue, taking precautions to include the mass of any loose residue which may have fallen off. Any loose residue lying in the tray shall be assigned to this mass if it can be established that it has definitely come from this
40、 particular specimen and not from one of its neighbours. The mean mass of the infiltrated specimens is given the symbol m3.Remove all loose residue by inverting the infiltrated specimens and reweigh with the loose residue absent. In the case of a residue-free powder, the infiltrated specimens can be
41、 weighed as they are. Those infiltrants which produce a slightly adherent “button” will require a scraping action to remove this form of residue before weighing the specimen. The mean mass of the cleaned infiltrated specimens is given the symbol m4.Examine the infiltrated specimen surfaces, especial
42、ly the one that has been in contact with the infiltrant compact, using approximately 10 magnification. Record the presence of adherent residue. Evaluate and note the amount of erosion. The different erosion ratings shall be established by agreement between the parties concerned. In addition to repor
43、ting erosion rankings, data shall also be reported as to the amount of infiltrant entry per unit area which produced that erosion rating. The amount of erosion tends to increase as the amount of infiltrant per unit area increases.NOTE Generally, any infiltrant is considered unacceptable if there is
44、any residue adherent to the infiltrated part. This can be determined by inspection as described above. If quantitative measures are desired, the amount of adhering residue can be determined by the difference in mass before and after removing any adherent residue by grinding or filing.6.5 Accurately
45、measure the dimensions of the infiltrated specimens.The change in dimensions of the infiltrated test specimens may be determined by calculating the change in dimensions before and after infiltration and is expressed as a percentage. The dimensional change can also be reported as the change in dimens
46、ions after infiltration based on the die dimensions using the formulae given in ISO 4492.6.6 Determine the density of the infiltrated specimen either by calculation from the mass and dimensions or by weighing in air and water as described in ISO 2738.6.7 Determine the transverse rupture strength of
47、the infiltrated specimens using the procedure described in ISO 3325 when the transverse rupture specimen is used (see 5.4).ISO 14168:2011(E) ISO 2011 All rights reserved 3BS ISO 14168:20116.8 Determine the hardness of the infiltrated specimens using the procedures described in ISO 4498. The location
48、 of the positions for hardness determination shall be a matter of agreement between the parties concerned.7 Calculation and expression of results7.1 Calculate the gross infiltration efficiency by the following formula:Efficiency, % = m mm4 21100wherem4is the mass of the infiltrated specimen, in gram
49、s, after residue has been removed;m2is the mass of the sintered, uninfiltrated specimen, in grams (see 6.2);m1is the mass of the infiltrant compact, in grams.7.2 Calculate the loose residue amount as follows:Residue, % = 3m mm41100wherem3is the mass of the infiltrated specimen, plus all residue, in grams;m4is the mass of the infiltrated specimen, in grams, after residue has been removed;m1is the mass of the infiltrant compact, in grams.8 Test reportThe test report shall contain the following information:a) composition, ma
