1、Designation: F2886 10Standard Specification forMetal Injection Molded Cobalt-28Chromium-6MolybdenumComponents for Surgical Implant Applications1This standard is issued under the fixed designation F2886; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the chemical, mechanical, andmetallurgical requirements for
3、metal injection molded (MIM)cobalt-28chromium-6molybdenum components to be used inthe manufacture of surgical implants1.2 The MIM components covered by this specification mayhave been densified beyond their as-sintered density by post-sinter processing.1.3 The values stated in either SI units or inc
4、h-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.2. Referenced Documents2.1 ASTM St
5、andards:2B243 Terminology of Powder MetallurgyB311 Test Method for Density of Powder Metallurgy (PM)Materials Containing Less Than Two Percent PorosityB923 Test Method for Metal Powder Skeletal Density byHelium or Nitrogen PycnometryE3 Guide for Preparation of Metallographic SpecimensE8/E8M Test Met
6、hods for Tension Testing of MetallicMaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE165 Practice for Liquid Penetrant Examination for GeneralIndustryE354 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and Othe
7、r Similar Iron,Nickel, and Cobalt AlloysE407 Practice for Microetching Metals and AlloysF75 Specification for Cobalt-28 Chromium-6 MolybdenumAlloy Castings and Casting Alloy for Surgical Implants(UNS R30075)F601 Practice for Fluorescent Penetrant Inspection of Me-tallic Surgical ImplantsF629 Practic
8、e for Radiography of Cast Metallic SurgicalImplantsF1537 Specification for Wrought Cobalt-28Chromium-6MolybdenumAlloys for Surgical Implants (UNS R31537,UNS R31538, and UNS R31539)SI 10 American National Standard for Use of the Interna-tional System of Units (SI): The Modern Metric System2.2 ISO Sta
9、ndards:3ISO 6892 Metallic Materials Tensile Testing at AmbientTemperatureISO 9001 Quality Management SystemsRequirements2.3 AMS Standards:4AMS 2269 Chemical Check Analysis Limits, Nickel,Nickel Alloys and Cobalt AlloysAMS 2248 Chemical CheckAnalysis Limits, Corrosion andHeat Resistant Steels and All
10、oys, Maraging and OtherHighly-Alloyed Steels, and Iron Alloys2.4 MPIF Standards:5MPIF Standard 10 Determination of the Tensile Propertiesof Powder Metallurgy MaterialsMPIF Standard 42 Determination of Density of Compactedor Sintered Powder Metallurgy ProductsMPIF Standard 50 Preparing and Evaluating
11、 Metal Injec-tion Molded Sintered/Heat Treated Tension SpecimensMPIF Standard 63 Density Determinations of MIM Com-ponents (Gas Pycnometry)1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee
12、F04.12 on Metallurgical Materials.Current edition approved Dec. 1, 2010. Published January 2011. DOI 10.1520/F288610.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to
13、 the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from American Society for Quality (ASQ), 600 N. Plankinton Ave.,Milwaukee, WI 53203, http:/www.asq.org.5Av
14、ailable from Metal Powder Industries Federation (MPIF), 105 College RoadEast, Princeton, New Jersey 08540, http:/www.mpif.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.MPIF Standard 64 Terms Used in Metal Injection Molding3. Te
15、rminology3.1 Definitions of Terms Specific to This Standard:3.2 Definitions of powder metallurgy and MIM terms can befound in Terminology B243 and MPIF Standard 64.Additionaldescriptive information is available in the Related MaterialSection of Vol. 02.05 of the Annual Book of ASTM Standards.3.3 abs
16、olute density, nthe value of density used to char-acterize a powder material with a particular chemical compo-sition as if it were a fully dense material, completely free ofporosity.3.3.1 DiscussionFor purposes of this specification, theskeletal density (also referred to as pycnometer density)measur
17、ed on the raw material powders using the pycnometrymethod of Test Method B923 will be used to represent theabsolute density of the particular chemical composition.3.4 debinding, na step between molding and sinteringwhere the majority of the binder used in molding is extractedby heat, solvent, a cata
18、lyst or other techniques.3.5 feedstock, nin metal injection molding, a moldablemixture of metal powder and binder.3.6 feedstock batch, na specified quantity of feedstockmade up of the same lot of metallic powders and the same lotof binder materials mixed under the same conditions atessentially the s
19、ame time.3.7 lot, na specified quantity of components made up ofthe same batch of feedstock, debound, sintered and postprocessed under the same conditions at essentially the sametime.3.8 metal injection molded component, nproduct fabri-cated by a metal injection molding process consisting ofmixing m
20、etal powders with binders to make a feedstock,introducing this feedstock into a mold by injection or othermeans, debinding to remove the binders, and sintering.3.9 pre-alloyed powder, npowder composed of two ormore elements that are alloyed in the powder manufacturingprocess in which the particles a
21、re of the same nominalcomposition throughout.3.10 relative density, nthe density ratio, often expressedas a percentage, of the density of a porous material to theabsolute density of the same material, completely free ofporosity.3.11 sinteringthe metallurgical bonding of particles in aMIM component r
22、esulting from a thermal treatment at atemperature below the melting point of the main constituent.4. Ordering Information4.1 Include with inquiries and orders for material under thisspecification the following information:4.1.1 Quantity,4.1.2 ASTM specification and date of issue,4.1.3 Alloy 1 (low c
23、arbon) or Alloy 2 (high carbon),4.1.4 Units to be certifiedSI or inch-pound,4.1.5 Component configuration (engineering drawingand/or 3D solid model) and dimensional requirements,4.1.6 Condition (5.3),4.1.7 Mechanical properties (if applicable),4.1.8 Finish (5.3),4.1.9 Special Tests (Section 9, Secti
24、on 10), if any, and4.1.10 Other requirements.5. Materials and Manufacture5.1 Components conforming to this specification shall beproduced by the metal injection molding process using preal-loyed metal powders with major elemental composition meet-ing the chemical requirements of Table 1.5.2 Post-sin
25、tering operations may be employed to achievethe desired density, shape, size, surface finish or other compo-nent properties. The post-sintering operations to be used shallbe agreed upon between the supplier and purchaser.5.3 The condition and finish of the components shall beagreed upon between the
26、supplier and purchaser.6. Chemical Requirements6.1 The components supplied under this specification shallconform to the chemical requirements in Table 1. The suppliershall not ship components with chemistry outside the require-ments specified in Table 1.6.1.1 Chemical analysis of the finished compon
27、ent or rep-resentative sample shall be used for reporting all chemicalrequirements. Any representative sample shall be producedfrom the same feedstock batch, debound, sintered, and postprocessed concurrently with the finished components that itrepresents.6.1.2 Requirements for the major and minor el
28、ementalconstituents are listed in Table 1. Also listed are importantresidual elements. The percentage of cobalt is determined bydifference and need not be determined or certified.6.1.3 Analysis for elements not listed in Table 1 is notrequired to verify compliance with this specification.6.2 Product
29、 Analysis:6.2.1 Product analysis tolerances do not broaden the speci-fied heat analysis requirements but cover variations in themeasurement of chemical content between laboratories. Theproduct analysis tolerances shall conform to the producttolerances in Table 2.TABLE 1 Chemical RequirementsElement
30、Chemical CompositionAlloy 1(Low Carbon)(% mass/mass)Chemical CompositionAlloy 2(High Carbon)(% mass/mass)min max min maxCarbon . 0.14 0.15 0.35Chromium 27.0 30.0 27.0 30.0Molybdenum 5.0 7.0 5.0 7.0Nickel . 0.5 . 0.5Iron . 0.75 . 0.75Silicon . 1.0 . 1.0Manganese . 1.0 . 1.0Tungsten . 0.20 . 0.20Phosp
31、horus . 0.020 . 0.020Sulfur . 0.010 . 0.010Nitrogen . 0.25 . 0.25Aluminum . 0.10 . 0.10Titanium . 0.10 . 0.10Boron . 0.010 . 0.010CobaltA. Balance . BalanceAThe percentage of cobalt is determined by difference and need not bedetermined or certified.F2886 1026.2.2 The product analysis is either for t
32、he purpose ofverifying the composition of the manufacturing lot or todetermine variations in the composition within the lot. Accep-tance or rejection of the manufacturing lot of components maybe made by the purchaser on the basis of this product analysis.6.2.3 Samples for chemical analysis shall be
33、representativeof the components being tested.6.2.4 Product analysis outside the tolerance limits allowedin Table 2 is cause for rejection of the product. A refereeanalysis may be used if agreed upon by the supplier andpurchaser.6.2.5 For referee purposes, use Test Methods E354, or otheranalytical me
34、thods agreed upon between the purchaser and thesupplier.7. Mechanical Requirements7.1 Tensile Properties:7.1.1 The components supplied under this specificationshall conform to the mechanical property requirements in Table3.7.1.2 Test specimens shall be taken from a MIM componentif possible, or from
35、a representative sample or molded tensilespecimen. A representative sample or molded tensile specimenmay only be used if the component configuration is such thata tensile specimen cannot be obtained from the component.7.2 Representative samples or molded tensile specimensshall be produced from the s
36、ame feedstock batch, debound,sintered and post processed concurrently with the finishedcomponents that they represent.7.2.1 Test specimens machined from components or repre-sentative samples shall be ground, or machined to finaldimensions in accordance Test Methods E8/E8M.7.2.2 Alternate tensile spe
37、cimen geometries may be agreedupon by the purchaser and supplier. Some examples of theconfigurations for molded tensile specimens are described inMPIF Standard 10 and MPIF Standard 50.7.3 Specimens for tensile tests shall be tested in accordancewith Test Methods E8/E8M.7.4 Should any test piece not
38、meet the specified require-ments, test two additional representative test pieces, in thesame manner, for each failed test piece. The lot shall beconsidered in compliance only if all additional test pieces meetthe specified requirements.7.5 Tensile tests result for which any specimen fracturesoutside
39、 the gauge length shall be considered valid, if both theelongation and reduction of area meet the minimum require-ments specified. If either the elongation or reduction of area isless than the minimum requirement, invalidate the specimenand retest. Retest one specimen for each invalidated specimen.8
40、. Dimensions and Permissible Variation8.1 Units of Measure:8.2 SelectionThis specification requires that the purchaserselects the units (SI or inch-pound) to be used for productcertification. In the absence of a stated selection of units on thepurchase order, this selection may be expressed by the p
41、ur-chaser in several alternate forms listed in order of precedence.8.3 If the purchaser and supplier have a history of usingspecific units, these units shall continue to be certified untilexpressly changed by the purchaser.8.4 In the absence of historic precedence, if the units used todefine the pro
42、duct on the purchasers purchase order, specifi-cation, and engineering drawing are consistent, these unitsshall be used by the supplier for product certification.8.5 If the purchasers selection of units is unclear, the unitsof measure shall be agreed upon between the purchaser andsupplier.8.6 Conver
43、sion of UnitsIf the suppliers test equipmentdoes not report in the selected units, the test equipment unitsmay be converted to the selected units for certification pur-poses. Accurate arithmetic conversion and proper use ofsignificant digits should be observed when performing thisconversion. ASTM SI
44、 10 provides guidelines for the use of SIunits. Annex A provides conversion tables and Annex Bprovides rules for conversion and significant digits.9. Microstructure9.1 The microstructural requirements and frequency of ex-aminations shall be mutually agreed upon by the supplier andpurchaser. Specimen
45、 preparation shall be in accordance withGuide E3 and Practice E407.TABLE 2 Product Analysis ToleranceA,BElement Tolerance Under the Minimum orOver the Maximum LimitComposition (% mass/mass)CCarbon 0.02Chromium 0.30Molybdenum 0.15Nickel 0.05Iron 0.03Silicon 0.05Manganese 0.03Tungsten 0.04Phosphorus 0
46、.005Sulfur 0.003NitrogenD0.02Aluminum 0.02Titanium 0.02Boron 0.002ASee Test Method E354.BSee AMS 2269 for chemical check analysis limits except nitrogen.CUnder minimum limit not applicable for elements where only a maximumpercentage is indicated.DRefer to AMS 2248.TABLE 3 Mechanical RequirementsRela
47、tive DensityAlloy 1 (Low Carbon) Alloy 2 (High Carbon)MPa (psi) MPA (psi)Ultimate Tensile Strength 725 (105 000) min 825 (120 000) minYield Strength (0.2 % offset) 450 (65 000) min 480 (70 000) minElongationA10 % min 10 % minReduction of Area 10 % min 10 % minAElongation of material 1.575 mm 0.062 i
48、n. or greater in diameter (D) or width(W) shall be measured using a gage length of 2 in. or 4D or 4W. The gage lengthshall be reported with the test results. The method for determining elongation ofmaterial under 1.575 mm 0.062 in. in diameter or thickness may be negotiated.Alternatively, a gage len
49、gth corresponding to ISO 6892 (5.65 times the square rootof So, where So is the original cross-sectional area) may be used when agreedupon between the supplier and purchaser.F2886 10310. Density10.1 The relative density of the finished components shallbe a minimum of 98 % of the absolute density of the prealloyedmetal powder lot used to make the components.10.2 The density of the finished components shall be mea-sured per Test Method B311, MPIF Standard 42,orMPIFStandard 63.10.3 The absolute density of the prealloyed metal powdershall be measured in accordan
