2024年6月14日发(作者：)

Designation:B106–96(Reapproved2002)

e1

StandardTestMethodsfor

FlexivityofThermostatMetals

1

ThisstandardisissuedunderthefixeddesignationB106;thenumberimmediatelyfollowingthedesignationindicatestheyearof

originaladoptionor,inthecaseofrevision,rinparenthesesindicatestheyearoflastreapproval.A

superscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.

e

1

N

OTE

—Paragraph1.3wascorrectededitoriallyinJune2002.

1.1Thesetestmethodscoverthedeterminationofflexivity

(ameasureofthermaldeflectionrateordeflectiontemperature

characteristics)ofthermostatmetals.

1.1.1TestMethodA—Testedintheformofflatstrip0.012

in.(0.30mm)oroverinthickness.

1.1.2TestMethodB—Testedintheformofspiralcoilsless

kness.

1.2Thevaluesstatedininch-poundunitsaretoberegarded

uesgiveninparenthesesareprovided

forinformationpurposesonly.

1.3Thisstandarddoesnotpurporttoaddressallofthe

safetyconcerns,ifany,e

responsibilityoftheuserofthisstandardtobecomefamiliar

withallhazardsincludingthoseidentifiedintheappropriate

MaterialSafetyDataSheetforthisproduct/materialaspro-

videdbythemanufacturer,toestablishappropriatesafetyand

healthpractices,anddeterminetheapplicabilityofregulatory

limitationspriortouse.

ncedDocuments

2.1ASTMStandards:

B389TestMethodforThermalDeflectionRateofSpiral

andHelicalCoilsofThermostatMetal

2

ology

3.1Definitions:

3.1.1thermostatmetal—acompositematerialintheformof

sheetorstripcomprisingtwoormoremetalliclayersof

differingcoefficientsofthermalexpansion,suchthattheradius

ofcurvatureofthecompositechangeswithtemperature

change.

ThesetestmethodsareunderthejurisdictionofASTMCommitteeB02on

NonferrousMetalsandAlloysandisthedirectresponsibilityofSubcommittee

B02.10onThermostatMetalandElectricalResistanceHeatingMaterials.

CurrenteditionapprovedJan.10,ally

publishedasB106–eviouseditionB106–90.

2

AnnualBookofASTMStandards,Vol02.04.

1

3.1.2flexivity(F)—thechangeofcurvatureofthelongitu-

dinalcenterlineofthespecimenperunittemperaturechange

forunitthickness,givenbythefollowingequation:

F5t

~

1/R

2

!

2

~

1/R

1

!

T

2

2T

1

(1)

Todeterminetheflexivitybetweenanytwotemperatures,T

1

andT

2

,itisnecessarytomeasurethecurvature1/R

1

and1/R

2

attemperatureT

1

andT

2

,findthecurvatureat

eithertemperature(Fig.1andFig.2),measurethedistanceD.

Thecurvatureisgivenbythefollowingequation:

1/R58D/

~

Q

2

14Dt14D

2

!

(2)

where:

R=radiusofcurvatureofthelongitudinalcenterlineof

thespecimen,in.(mm),

t=thicknessoftestspecimen,in.(mm),

Q=distancebetweensupportpoints,in.(mm),and

D=forpointsupport(simplysupported

beam),=perpendiculardistancebetweenthelongitu-

dinalcenterlinesofthelowersurfaceofthespecimen

midwaybetweenthepointsupportsandthestraight

linejoiningthesupportpoints,in.(mm).

ficanceandUse

4.1Thesetestmethodsareusedfordeterminingresponseto

temperaturechangeorfl

flexivityiscalculatedfromthetemperatures,dimensionsof

specimen,

simplebeammethodisthemethodforcertifiof

thespiralcoilmethod(MethodB)istobemutuallyagreed

uponbetweentheuserandsupplier.

TESTMETHODA—FLATSTRIPS

tus

5.1SpecimenCarrier,providedwithtwoconicalsupports

tlength(thatis,thedistance

betweenthepointofcontactofthespecimenwithonesupport

andthepointofcontactofthespecimenwiththeothersupport)

Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.

1

FIG.1TestforFlexivityofThermostatMetals

FIG.2TypicalApparatusDesign

shallbeknowntowithin60.005in.(0.13mm),andthelineof

planepassingthroughthepointsofcontactshallbehorizontal.

Thespecimencarrierandsupportsshallholdthespecimen

withoutconstraintsothatthecurvature,duetoitsdeflection,

willfollowaverticalplanepassingthroughthelinejoiningthe

pointsofcontactbetweenspecimenandsupports.

5.2Micrometer—travelingmicroscope,orequivalentde-

vice,soconnectedtothespecimencarrierthatexpansion

duringheatingofthecarrierorconnectingpartswillnotcause

appreciabledisplacementofthemeasuringdevicewithrespect

tothesupports.

5.3Bath—Astirredliquidbathoruniformlyheatedenclo-

sureinwhichthespecimencarrier,togetherwithadjustable

cimenneedstobe

maintainedatthedesiredtemperatures,withavariationin

temperaturethroughoutthegagelengthofthespecimennotto

exceed0.5%ofthetemperaturerangeusedinthetest.

5.4TemperatureMeasuringApparatus,ofsuchaccuracy

thattheindividualtemperaturesshallbeknowntowithin

60.5°F(0.3°C).

5.5DeflectionIndex—Meansshallbeprovidedformeasur-

ingthedeflectionofthespecimenatapointmidwaybetween

thepointsofsupportandalongtheverticallineintersectingthe

ansmaycomprisea

fused-quartztransmissionroddisposedwithitsaxisvertical

andterminatinginapointorknife-edge,whichshallengage

thespecimenmidwaybetweenthepointsofcontactwiththe

supports.

5.5.1Thetransmissionrodshallbemountedinsucha

rodshallbearatitsfreeendanindexsuitableformicroscopical

observation,orelseanelectricalcontactwithwhichami-

crometerwillpermitthechangesofthedeflectionofspecimen

atively,thedeflectionofthe

midpointofthespecimenmaybedirectlyobservedbyoptical

meanswhoselineofsightishorizontalandpassesthroughthe

me-

terscrewwithextendedspindlemakingdirectcontactwiththe

case,electricalmeansshallbe

providedthatwillindicatecontactwithoutsignificantdistur-

surementofthepositionofthe

midpointofthetestspecimenshallbeofsuchaccuracythatthe

individualpositionsatthetesttemperaturesshallbeknownto

within60.0002in.(0.005mm).

5.5.2Ifatransmissionrodisused,itandanyattachedparts

shallbeofsuchweightorsocounterweightedthattheywillnot

causeadeflectiongreaterthan1%ofthemaximumtobe

free,thethermostatmetalassumedverynearlyacircular

tratedloadingatthecenterofthespecimen

willcausethecurvaturetobeotherthancircularandmaycause

significanterrorsintheevaluationofflationof

thelinepassingthroughthepointsofcontactbetweenspeci-

menandsupportsshallbeknown,withreferencetothescaleof

themicrometer,towithin60.002in.(0.05mm).

5.6Allmetalliccomponentsoftheflexivityapparatus

shouldbemadeofverylowcoefficientofthermalexpansion

ommendedmaterialisinvar.

ecimens

6.1Thetestspecimenshallbeintheformofastripthat

displaysnoapparentinitialirregularityofcurvature.

6.2Themaximumthicknessshallnotbegreaterthanthe

minimumthicknessbymorethan1%ofthelatter.

6.3Thewidthshallberelatedtothethicknessinaccordance

redwidthsaretobeusedwheneverpossible.

Themaximumwidthshallnotexceedtheminimumwidthby

morethan2%ofthelatter.

6.4Thelengthshallbesuchastoallowadistancebetween

supportsthatbearstherelationtothethicknessinaccordance

withTable1andtoallowadistancebeyondthesupportsnot

lessthanthewidth.

6.5Thethicknessofthespecimenshallbedetermined

within60.0001in.(0.002mm)bymeansofascrewmicrome-

teroranequivalentmethod.

6.5.1Forspecimenslessthan0.050in.(1.27mm)in

thickness,specialprecautionsarenecessary,suchastheuseof

amicrometerreadingdirectlyto0.0001in.(0.002mm).

Suitableopticalmethodsmayalsobeused.