ASTM_C_539_-_84_2016.pdf

Designation:C53984(Reapproved 2016)Standard Test Method forLinear Thermal Expansion of Porcelain Enamel and GlazeFrits and Ceramic Whiteware Materials by InterferometricMethod1This standard is issued under the fixed designation C539;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 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 interferometric determina-tion of linear thermal expansion of premelted frits(porcelainenamel and glaze)and fired ceramic whiteware materials attemperatures lower than 1000C(1830F).1.2 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E289 Test Method for Linear Thermal Expansion of RigidSolids with Interferometry3.Significance and Use3.1 This test method defines the thermal expansion ofporcelain enamel and glaze frits by the interferometric method.This determination is critical in avoiding crazing(cracking)ofthese glass coatings due to mismatching of the thermalexpansion between the coating and substrate materials.4.Apparatus4.1 Sample Preparation Equipment:34.1.1 Glazed Porcelain Crucible,No.0.4.1.2 Fireclay Crucible,102 mm(4 in.)in diameter.4.1.3 Rotating Abrasive Grinding Wheel(a silicon carbidetype is satisfactory).4.2 Micrometer Calipers,having a sensitivity such that theindex can be read to 0.002 mm(0.0001 in.).4.3 Measuring Apparatus,consisting of fused silica inter-ferometer plates,viewing apparatus,an electric furnace andcontrol,potentiometer,pyrometer,and a suitable monochro-matic light source of known wavelength.4.3.1 FurnaceThe furnace shall be a vertical electric tubefurnace controlled by rheostat or other means so the heatingrate of the furnace can be readily duplicated from roomtemperature to 1000C(1830F).The heating rate shall notexceed 3C(5.5F)/min.4.3.2 Temperature Measuring Instrument A calibratedplatinum versus platinum-rhodium thermocouple(or aChromel versus Alumel thermocouple if it is frequently cali-brated)in conjunction with a potentiometer shall be used.Thepotentiometer shall be capable of being read to 2C(4F)andshall have automatic compensation for the temperature of thereference junction,or the reference junction shall be held at0C(32F)by means of an ice bath.5.Test Specimens5.1 For frit samples,three test specimens shall be preparedas follows:5.1.1 Fill a No.0 glazed porcelain crucible with frit,placethe filled crucible inside a 102-mm(4-in.)diameter fireclaycrucible partly filled with silica,and work the small crucibledown into the silica until approximately 75%of the smallcrucible is below the level of the silica.5.1.2 Place the crucible assembly into a furnace at atemperature high enough to just melt the mass.Hold for 15 minafter the frit has reached the furnace temperature.5.1.3 Remove the crucible,rapidly transfer it to anotherfurnace that is at the frit firing temperature,and cool in thefurnace at a rate not to exceed 60C(110F)/h.5.1.4 Break the small crucible open and break up thevitreous mass.Select six fragments from the interior of themass(to avoid side portions diluted by the ceramic crucible)1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatingsand is the direct responsibility of Subcommittee B08.12 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved Nov.1,2016.Published November 2016.Originallyapproved in 1964.Last previous edition approved in 2011 as C539 84(2011).DOI:10.1520/C0539-84R16.2For 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 the standards Document Summary page onthe ASTM website.3An example of suitable test equipment and an inferometric method may befound in the paper by Merritt,G.E.,“The Interference Method of MeasuringThermal Expansion,”Journal of Research,National Institute of Standards andTechnology,Vol 10,No.1,January 1933,p.59(RP 515).A description of a permissible automatic fringe recording device may be foundin the paper by Saunders,J.B.,“An Apparatus for Photographing InterferencePhenomenon,”Journal of Research,National Institute for Standards andTechnology,Vol 35,No.3,September 1945,p.157(RP 1668).Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 having minimum conical dimensions of 3 mm(18in.)at thebase and 6 mm(14in.)high.5.2 For fired samples,break and select six samples havingminimum conical dimensions of 3 mm(18in.)at the base and6 mm(14in.)in height.For all