1、Designation: F 2094 06e1Standard Specification forSilicon Nitride Bearing Balls1This standard is issued under the fixed designation F 2094; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pare
2、ntheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTETable 2 was editorially corrected in June 2007.1. Scope1.1 This specification covers the establishment of the basicquality, physical/mechanical property,
3、and test requirementsfor silicon nitride balls Classes I, II, and III to be used for ballbearings and specialty ball applications.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system are not exact equivalents; therefor
4、e, each systemmust be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with thespecification.2. Referenced Documents2.1 Order of Precedence:2.1.1 In the event of a conflict between the test of thisdocument and the references herein, the text of this
5、documenttakes precedence. Nothing in this document, however, super-sedes applicable laws and regulations unless a specific exemp-tion has been obtained.2.2 ASTM Standards:2C 373 Test Method for Water Absorption, Bulk Density,Apparent Porosity, and Apparent Specific Gravity of FiredWhiteware Products
6、C 1161 Test Method for Flexural Strength of AdvancedCeramics at Ambient TemperatureC 1198 Test Method for Dynamic Youngs Modulus, ShearModulus, and Poissons Ratio for Advanced Ceramics bySonic ResonanceC 1239 Practice for Reporting Uniaxial Strength Data andEstimating Weibull Distribution Parameters
7、 for AdvancedCeramicsC 1327 Test Method for Vickers Indentation Hardness ofAdvanced CeramicsC 1421 Test Methods for Determination of Fracture Tough-ness of Advanced Ceramics at Ambient TemperatureE 165 Test Method for Liquid Penetrant ExaminationE 384 Test Method for Microindentation Hardness of Ma-
8、terialsE 831 Test Method for Linear Thermal Expansion of SolidMaterials by Thermomechanical AnalysisE 1417 Practice for Liquid Penetrant Testing2.3 ANSI Standard:ANSI/ASQC Z1.4 Sampling Procedures and Tables forInspection by Attributes32.4 ABMA Standards:STD 1 Terminology for Anti-Friction Ball and
9、Roller Bear-ings and Parts4STD 10 Metal Balls42.5 ASME Standard:B 46.1 Surface Texture (Surface Roughness, Waviness, andLay)52.6 DIN Standards:65401 Rolling Bearings; Balls of Through-Hardening Roll-ing Bearing Steel, Part 15401 Rolling Bearings; Balls of Through-Hardening Roll-ing Bearing Steel, Pa
10、rt 22.7 ISO Standards:3290 Rolling Bearings, Bearing Parts, Balls for RollingBearings34505 HardmetalsMetallographic Determination of Poros-ity and Uncombined Carbon32.8 JIS Standards:R 1601 Testing Method for Flexural Strength (Modulus ofRupture) of High Performance Ceramics71This specification is u
11、nder the jurisdiction ofASTM Committee F34 on RollingElement Bearings and is the direct responsibility of Subcommittee F34.01 onRolling Element.Current edition approved Nov. 1, 2006. Published December 2006. Originallyapproved in 2001. Last previous edition approved in 2003 as F 2094 03a.2For refere
12、nced 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 the standards Document Summary page onthe ASTM website.3Application for copies should be addressed to theAmerican National Stan
13、dardsInstitute, 25 West 43rd Street, 4th Floor, New York, NY 10036.4Application for copies should be addressed to the American Bearing Manufac-turers Association, 1200 19th Street NW, Suite 300, Washington, DC 20036-2401.5Application for copies should be addressed to the American Society ofMechanica
14、l Engineers, 345 East Street, New York, NY 10017.6Application for copies should be addressed to the Deutsches Institut FrNormung (German Standards Institute), Burggrafenstrasse 6, D 10787 Berlin,Germany.7Application for copies should be addressed to the Japanese Standards Associa-tion, 1-24 Akasaka
15、4 chome, Minato-ku, Tokyo. 107 Japan.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.R 1602 Testing Method for Elastic Modulus of High Per-formance Ceramics7R 1603 Methods for Chemical Analysis of Fine SiliconNitride Powders for Fine
16、 Ceramics7R 1607 Testing Method for Fracture Toughness of HighPerformance Ceramics7R 1610 Testing Method for Vickers Hardness of HighPerformance Ceramics7R 1611 Testing Methods of Thermal Diffusivity, SpecificHeat Capacity and Thermal Conductivity for High Perfor-mance Ceramics by Laser Flash Method
17、7R 1618 Measuring Method of Thermal Expansion of FineCeramics by Thermomechanical Analysis7R 1624 Weibull Statistics of Strength Data for Fine Ceram-ics72.9 CEN Standards:EN 843-1 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 1. Determination of Flexural
18、 Strength8EN 843-2 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 2 Determination of Elastic Moduli8ENV 843-4 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 4. Vickers, Knoop and Rockwell Superficial HardnessTe
19、sts8ENV 843-5 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 5, Statistical Analysis8EN 623-2 Advanced Technical CeramicsMonolithicCeramicsGeneral and Textural PropertiesDetermination of Density and Porosity8EN 821-2 Advanced Technical CeramicsMonolithicC
20、eramicsThermo-physical PropertiesPart 2: Deter-mination of Thermal Diffusivity by the Laser Flash (orHeat Pulse) method8EN 821-1 Advanced Technical CeramicsMonolithicCeramicsThermo-physical PropertiesPart 1: Deter-mination of Thermal Expansion83. Terminology3.1 Definitions of Terms Specific to This
21、Standard:3.1.1 ball diameter variation (Vdws)ball diameter varia-tion is the difference between the largest and smallest diametermeasured on the same ball.3.1.2 ball gage (S)prescribed small amount by which thelot mean diameter should differ from nominal diameter, thisamount being one of an establis
22、hed series of amounts. A ballgage, in combination with the ball grade and nominal balldiameter, should be considered as the most exact ball sizespecification to be used by a customer for ordering purposes.3.1.3 ball gage deviation (DS)difference between the lotmean diameter and the sum of the nomina
23、l diameter and theball gage.3.1.4 ball grade (G)specific combination of dimensionalform and surface roughness tolerances. A ball grade is desig-nated by a grade number followed by the letter “C” indicatingSilicon Nitride Ceramic.3.1.5 blank lotsingle group of same-sized ball blanksprocessed together
24、 from one material lot through densification.3.1.6 deviation from spherical form (DRw)greatest radialdistance in any radial plane between a sphere circumscribedaround the ball surface and any point on the ball surface.3.1.7 finish lotsingle group of same-sized balls (whichmay be derived from multipl
25、e blank lots of the same materiallot) processed together through finishing.3.1.8 lot diameter variation (Vdwl)difference between themean diameter of the largest ball and that of the smallest ballin the lot.3.1.9 lot mean diameter (Dwml)arithmetic mean of themean diameter of the largest ball and that
26、 of the smallest ballin the lot.3.1.10 material lotsingle process lot of silicon nitride rawpowder received from a material supplier.3.1.11 mean diameter of a ball (Dwm)arithmetic mean ofthe largest and the smallest actual single diameters of the ball.3.1.12 nominal diameter (Dw)size ordered that is
27、 thebasis to which the nominal diameter tolerances apply. Thenominal diameter is specified in inches or millimeters (decimalform).3.1.13 nominal diameter tolerancemaximum allowabledeviation from true specified nominal diameter for the indi-cated grade.3.1.14 single diameter of a ball (Dws)the distan
28、ce be-tween two parallel planes tangent to the surface of the ball.3.1.15 surface roughness (Ra)surface irregularities withrelative small spacings, which usually include irregularitiesresulting from the method of manufacture being used or otherinfluences, or both.3.1.16 unit containercontainer ident
29、ified as containingballs from the same manufacture lot of the same composition,grade, and nominal diameter, and within the allowable diam-eter variation per unit container for the specified grade.4. Classification4.1 Silicon nitride materials for bearing and specialty ballapplications are specified
30、according to the following materialclasses (see Appendix X1 for typical current applications):4.1.1 Class IHighest grade of material in terms of prop-erties and microstructure. Suitable for use in the most demand-ing applications. This group adds high reliability and durabilityfor extreme performanc
31、e requirements.4.1.2 Class IIGeneral class of material for most bearingand specialty ball applications. This group addresses theconcerns of ball defects as is relative to fatigue life, levels oftorque, and noise.4.1.3 Class IIILower grade of material for low dutyapplications only. This group of appl
32、ications primarily takesadvantage of silicon nitride material properties. For example:Light weight, chemical inertness, lubricant life extension dueto dissimilarity with race materials, etc.8Application for copies should be addressed to the British Standards Institute,389 Chiswick High Road, London,
33、 W4 4AL, UK.F209406e125. Ordering Information5.1 Acquisition documents should specify the following:5.1.1 Title, number, and date of this specification.5.1.2 Class, grade, and size (see 4.1, 8.6, and 8.7).6. Material6.1 Unless otherwise specified, physical and mechanicalproperty requirements will ap
34、ply to all material classes.6.2 Silicon nitride balls should be produced from eithersilicon nitride powder having the compositional limits listed inTable 1 or from silicon metal powder, which after nitridationcomplies with the compositional limits listed in Table 1.6.3 Composition is measured in wei
35、ght percent. Testingshall be carried out by a facility qualified and approved by thesupplier. Specific equipment, tests, and/or methods are subjectto agreement between suppliers and their customers.6.4 The following compounds may be added to promotedensification and/or enhance product performance an
36、d quality.The following may be added as oxides, nitrides, oxynitrides, ormixtures:6.4.1 Aluminum,6.4.2 Magnesium,6.4.3 Barium,6.4.4 Lanthanum,6.4.5 Yttrium,6.4.6 Calcium, and6.4.7 Other rare earths.6.5 The following may be added as nitrides, oxynitrides, orcarbonites:6.5.1 Titanium,6.5.2 Tantalum, a
37、nd6.5.3 Zirconium.6.6 Aluminum silicon oxynitrides (aluminum nitride poly-types) may be added to promote densification.6.7 Precautions should be taken to minimize contaminationby foreign materials during all stages of processing up to andincluding densification.6.8 A residual content of up to 2 % tu
38、ngsten carbide frompowder processing is allowable.6.9 Final composition shall meet and be reported accordingto the specification of the individual supplier.6.10 Notification will be made upon process changes.6.11 Specific requirements such as specific material gradedesignation, physical/mechanical p
39、roperty requirements (forexample, density) or quality or testing requirements shall beestablished by specific application. The special requirementsshall be in addition to the general requirements established inthis specification.6.12 Typical mechanical properties will fall within the rangelisted in
40、Table 2. Individual requirements may have tighterranges. The vendor shall certify that the silicon nitride materialsupplied has physical and mechanical properties within therange given in Table 2. In the case of properties indicated by(+), the provision of the data is not mandatory.7. Physical Prope
41、rties7.1 The following physical properties shall be measured, ata minimum, on each material lot.7.1.1 Average values for room temperature rupture strength(bend strength/modulus of rupture) for a minimum of 20individual determinations shall exceed the minimum valuesgiven in Table 3. Either 3-point or
42、 4-point test methods may beused for flexural strength, which should be measured inaccordance with Test Method C 1161 (size B), CEN 843-5, orJIS R 1601. Weibull modulus for each test series shall alsoexceed the minimum permitted values given in Table 3.Ifasample set of specimens for a material lot d
43、oes not meet theTABLE 1 Compositional LimitsAConstituents Limits (wt %)Silicon nitride 97.0 min.Free silicon 0.3 max.Carbon 0.3 maxIron 0.1 max.AOther impurities or elements such as sodium, potassium, chlorine, etc.individually shall not exceed 0.02 wt % max.TABLE 2 Typical Mechanical PropertiesAPro
44、perties Minimum MaximumDensity, g/cc (lb/ft3) 3.0 (187) 3.4 (212)Elastic modulus, GPa (ksi) 270 (39 150) 330 (47 850)Poissons ratio 0.23 0.29Thermal conductivity, W/m-K (Btu/h-ft-F) 20C (room temp.)20 (11.5) 38 (21.9)Specific heat, J/kg-K (Btu/Ibm-F)650 (0.167) 800 (0.191)Coefficient of thermal expa
45、nsion, 310-6/C(room temp. to 500C)2.3 3.4+ Resistivity, Ohm-m 10101016+ Compressive strength, MPa (ksi) 3000 (435)ASpecial material data should be obtained from individual suppliers.Editorially corrected in June 2007.TABLE 3 Minimum Values for Mean Flexural Strength andWeibull ModulusMaterial ClassU
46、nit I II IIITransverse-rupturestrengthA3 points3,40(s3,30)MPa 900 (920) 800 (825) 600 (625)Weibullmodulus12 9 7Transverse-rupturestrengthA4-points4,40(s4,30)MPa 700 (745) 600 (645) 450 (495)Weibullmodulus12 9 7AThe Flexural strength equivalents are based on Weibull volume or surfacescaling using the
47、 value of m for each cell and are rounded to the nearest 5 MPa.sn,L= denotes the flexure strength, n=3or4point,onspans of size L.s4,40= 660 MPa means the four point flexure strength, on 40 mm spans is 660MPa as per Test Method C 1161 (size B) and CEN EN 843-1.s4,30= 700 MPa means the four point flex
48、ure strength, on 30 mm spans is 700MPa as per JIS R 1601.F209406e13Weibull modulus requirement in Table 3, then a second sampleset may be tested to establish conformance.7.1.2 The hardness (HV) shall be determined by the Vickersmethod (see Annex A1) using a load of at least 5 kg but notexceeding 20
49、kg. Fracture resistance shall be measured byeither an indentation technique (seeAnnexA1) or by a standardfracture toughness test method. Average values for hardnessand fracture resistance shall exceed the minimum of values forthe specified material class given in Table 4.7.1.3 Microstructure constituents visible at magnification inthe range 3100 to 3200 shall not exceed the maximum valuesgiven in Table 5 for the specified material class.7.1.4 The number of ceramic metallic or mixed inclusionsobserved in transverse sections shal
