1、Designation: B223 08 (Reapproved 2013)Standard Test Method forModulus of Elasticity of Thermostat Metals (CantileverBeam Method)1This standard is issued under the fixed designation B223; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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 test method covers the determination of the modu-lus of elasticity of thermostat metals at any te
3、mperaturebetween 300 and +1000F (185 and 540C) by mounting thespecimen as a cantilever beam and measuring the deflectionwhen subjected to a mechanical load.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units
4、 that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to become familiarwith all hazards including those identified in the a
5、ppropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B388 Specification for Thermosta
6、t Metal Sheet and Strip3. Terminology3.1 Definitions:3.1.1 thermostat metal, na composite material, usually inthe form of sheet or strip, comprising two or more materials ofany appropriate nature, metallic or otherwise, which, by virtueof the differing expansivities of the components, tends to alter
7、its curvature when its temperature is changed.3.1.2 modulus of elasticity, nthe ratio, within the elasticlimit of a material, of stress to corresponding strain. In this testmethod the modulus of elasticity is calculated from theexpression for the deflection of a cantilever beam undermechanical load
8、which is transposed to read as follows:E 5 4Pl3/dbt3where:E = modulus of elasticity, psi or MPa,P = load, lbf or N,l = gage length, in. or mm,d = specimen deflection, in. or mm,b = specimen width, in. or mm, andt = specimen thickness, in. or mm.4. Apparatus (Figs. 1-3)4.1 Specimen Holder for securel
9、y clamping the test speci-men in a horizontal position as a cantilever beam whenimmersed in a bath at the desired temperature. It shall carry amicrometer depth gage for reading the deflection of thespecimen and a loading rod for loading the specimen. Both ofthese shall extend sufficiently above the
10、liquid level of the bathto permit the operator to perform the test at the higher testtemperatures.4.1.1 Specimen holder to be made sufficiently rigid to allownormal handling without distortion.4.2 Loading Rod,18 in. (3.2 mm) or less in diameter, forcarrying the load and transmitting its weight verti
11、cally to thefree end of the cantilever specimen. It shall be made of a lowexpansion material; the mounting clamp and tube shall bemade of the same material as the specimen mounting clamps inorder to prevent a difference in expansion rates from affectingthe deflection readings. The bottom end shall b
12、e conicallyshaped and shall rest in the conical punch mark at the free endof the specimen.Any supports shall permit free movement withspecimen deflection and shall provide electrical insulation fromthe micrometer depth gage. Near the top shall be a holder forsupporting the load. The weight of the lo
13、ading rod and holdershall be no greater than 1 oz (28 g).4.3 Micrometer Depth Gage, for measuring the deflection ofthe specimen to the nearest 0.0001 in. (0.002 mm). It shall bemounted directly over the loading rod. The micrometer shaftshall be in the same vertical line as the loading rod, so thatre
14、adings can be taken of the top of the loading rod for no-load1This test method is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.10 on Thermostat Metals and Electrical Resistance Heating Materials.Current edition approv
15、ed Aug. 1, 2013. Published August 2013. Originallyapproved in 1948. Last previous edition approved in 2008 as B223 08. DOI:10.1520/B0223-08R13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
16、lume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1and full-load positions. The gage shall be insulated electricallyfrom the specimen holder and the loadin
17、g rod.4.4 Load, constructed so that when placed in the holder, itscenter of gravity will coincide with the center of the loadingrod. It shall be readily detachable for the operators conve-nience in taking no-load and full-load readings and shall not beof sufficient weight to deflect the specimen mor
18、e than 0.30 in.(7.6 mm).4.5 BathA stirred liquid so that the temperature shall besubstantially constant during the test.4.6 Electronic Indicator, sensitive, low-current, to give asignal when the micrometer depth gage shaft completes theelectrical circuit across the indicator terminals by touching th
19、etop of the loading rod. The indicator sensitivity shall be suchthat loading rod positions can be determined with a precision of60.0001 in. (0.002 mm).4.7 All metallic components of apparatus, excluding mi-crometer and loads, should be made of very low coefficient ofthermal expansion materials. The
20、recommended material isinvar.5. Precautions5.1 Load and no-load readings of the various trials will notapproximately duplicate each other in the event the load issufficiently great to overstress the specimen beyond its elasticlimit. In this case a new specimen shall be substituted and alighter load
21、used which will not overstress the material.5.2 Modulus of elasticity measurements to be within themaximum recommended temperatures as stated in Specifica-tion B388.FIG. 1 Testing Machine for Determining Modulus of Elasticity of Thermostat MetalFIG. 2 Specimen Mounting Clamp AssemblyB223 08 (2013)26
22、. Test Specimen6.1 The test specimen shall be the form of a strip approxi-mately 114 in. (31.8 mm) longer than the gage length. Thethickness may be any value between 0.015 and 0.055 in. (0.38and 1.40 mm); however, corresponding width values shallconform with those in Fig. 4. Width and thickness dime
23、nsionsshall be determined with a precision of 60.0001 in. (0.002mm).7. Preparation of Specimen7.1 Gage LengthThe gage length shall be the distance onthe specimen between the center of the punch mark thatsupports the loading rod and the edge of the specimen holderclamps.This punch mark shall be appro
24、ximately one half of thethickness of the specimen deep and located on the center line14 in. (6.4 mm) from the free end on low expansion sidesurface. To obtain the necessary accuracy in gage length, theFIG. 3 Specimen Mounting Clamp DetailsFIG. 4 Width of Test SpecimenB223 08 (2013)3specimen shall be
25、 made as shown in Fig. 5 which, when thespecimen is placed in the specimen mounting clamps, willmaintain the gage length with a tolerance of 60.003 in. (0.08mm). Table 1 gives the gage lengths for various specimenthicknesses.NOTE 1For thicknesses, widths, and lengths not covered by this testmethod,
26、the procedure shall be agreed between the manufacturer and thepurchaser.7.2 After being roughly cut, slit, or sheared from the sample,the test specimen shall be finished to size by careful machiningor filing.7.3 Preforming OperationThe specimen shall be pre-formed into a shape approximating the segm
27、ent of a circle. Theamount of this preforming shall be such that, when subjected tothe desired temperature, the specimen will take an upwardcurvature sufficient to cause the no-load and full-load deflec-tion positions to be approximately equally distant above andbelow the straight position (Fig. 6).
28、7.4 Heat TreatmentAfter the preforming work has beencompleted the specimen shall be heat treated to relieve allinternal stresses. This treatment shall consist of heating thespecimen while free to bend at a prescribed temperature and fora prescribed time. Heat treatment shall be at least 50F higherth
29、an the maximum tested temperature at a soak time of 1 h. Thedetails of this procedure will depend on the characteristics ofthe thermostat metal and shall be mutually agreed upon by themanufacturer and the purchaser.7.5 MarkingAny identification marking shall be placed onthat part of the fixed end of
30、 the specimen not included in thegage length.8. Procedure8.1 CleaningCarefully remove any oxide coating andother foreign substances from all those surfaces which directlyaffect the electrical resistance of the electronic indicator circuitthrough the testing apparatus. This operation is necessary top
31、ermit maximum sensitivity of the indicator. The top of theloading rod which touches the micrometer depth gage shaftmay be ground to a point in order to further increase theindicator sensitivity.8.2 Test RoutineClamp the specimen securely in thespecimen holder using the 0.125-in. (3.18-mm) dowel hole
32、 and0.125-in. dowel pin for accurate positioning. Lower the bottompart of the specimen holder with the specimen into the bath ofthe desired temperature and support the apparatus rigidly. Placethe lower end of the loading rod in the punch mark at the freeend of the specimen. Connect the electronic in
33、dicator toterminals on the specimen holder. When satisfactory initialconditions have been established, adjust the micrometer depthgage until the electronic indicator signals that the gage shaft istouching the loading rod and record this position as the no-loadreading. Deflect the specimen by placing
34、 the load on the loadholder and record this position of the rod as the load reading.The difference between these two readings will be the amountof deflection. Obtain an average value of deflection from ten ormore trials.8.3 Calculation of Modulus of ElasticitySubstituting thespecimen size and the av
35、erage deflection for a known load inthe equation in 3.1.2, calculate the modulus of elasticity, E,asin the following example:FIG. 5 SpecimenTABLE 1 Gage Length of Test SpecimenSpecimen Thickness Gage Lengthin. mm in. mm0.015 to 0.0199, incl 0.38 to 0.509, incl 212 12 63.5 1.30.020 to 0.0249, incl 0.
36、51 to 0.639, incl 3 12 76.2 1.30.025 to 0.0299, incl 0.64 to 0.759, incl 312 12 88.9 1.30.030 to 0.0349, incl 0.76 to 0.889, incl 4 12 101.6 1.30.035 to 0.0449, incl 0.89 to 1.139, incl 412 12 114.3 1.30.045 to 0.055, incl 1.14 to 1.40, incl 5 12 127.0 1.3FIG. 6 Relationship of Specimen No-Load, Str
37、aight, and Full-Load Positions at Test TemperatureB223 08 (2013)4E 5 4Pl3/dbt3where:P = 4.00 ozf = 0.250 lbf or 1.112 N,l = 4.00 in. or 101.6 mm,d = 0.1863 in. or 4.732 mm,b = 0.5000 in. or 12.700 mm, andt = 0.0301 in. or 0.765 mm.Substituting the known values,E = (4 0.250 lbf (4.00 in.)3)/0.1863 in
38、. 0.500 in. (0.0301 in.)3)E = 25 194 029 psi.orE = (4 1.112 N (101.6 mm)3)/(4.732 mm 12.700 mm (0.765 mm)3)E = 173 386 MPa.9. Report9.1 The report shall include the following:9.1.1 Type of thermostat metal,9.1.2 Dimensions of specimen in inches or millimetres,9.1.3 Temperature of test,9.1.4 Directio
39、n of grain on specimen, and9.1.5 Modulus of elasticity in pounds-force per square inchor megapascals.10. Precision and Bias10.1 PrecisionThe precision of this test method wasperformed in accordance with the test procedure and loadknown to 60.04 % results in a 2-sigma measurement precisionof 61.8 %.1
40、0.2 BiasComparison to accepted reference values indi-cates lack of bias.11. Keywords11.1 cantilever; loading rod; modulus of elasticity; thermo-stat metalASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.
41、Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed ev
42、ery five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible tech
43、nical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
44、ken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B223 08 (2013)5
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