1、Designation:C82491(Reapproved 2015)Standard Practice forSpecimen Preparation for Determination of Linear ThermalExpansion of Vitreous Glass Enamels and Glass EnamelFrits by the Dilatometer Method1This standard is issued under the fixed designation C824;the number immediately following the designatio
2、n 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 practice covers the preparation of vit
3、reous glassenamels and glass enamel frit specimens for the measurementof linear thermal expansion using Test Method E228.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of th
4、esafety 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.For specific hazardstatements,see Section 6.2.Referenced Documents2.1 AST
5、M Standards:2E228 Test Method for Linear Thermal Expansion of SolidMaterials With a Push-Rod Dilatometer3.Significance and Use3.1 The dilatometer method of measuring linear thermalexpansion of vitreous glass enamels and glass enamel frits hasthe advantage of simplicity,lends itself to automatic,self
6、-recording arrangements,and requires test specimens of simpleconfiguration.4.Apparatus4.1 Powder Pressing Die,whose top and bottom sectionsare free to move such that density variations within the bar areminimized(see Fig.1).4.2 Hydraulic Press.4.3 Furnace,for firing test specimen,electrically heated
7、 andcontrolled to a minimum rate of heating of 1C/min from roomtemperature to the maximum temperature of the test.It shall beso designed that the temperature variation over the length ofthe test specimen shall be less than 2C during the entire rangeof heating.4.4 Scale or Caliper,capable of measurin
8、g the length of thetest specimen to an accuracy of 0.1%.5.Reagents and Materials5.1 Hydroxypropyl Cellulose Solution in Water(1 weight%).5.2 Powder Sample.6.Hazards6.1 Appropriate ventilation should be provided when han-dling powdered frits or enamels containing toxic ingredients.6.2 Ingestion or in
9、halation of test materials should beavoided.Protective clothing such as gloves,respirators,etc.,may be advisable.If ingestion occurs,seek medical attentionimmediately.6.3 Caution should be exercised when placing specimens infurnaces.Tongs and insulated gloves should be used.To avoidaccidental contac
10、t and serious thermal burns,care should betaken to guard hot-fired specimens while they are being cooled.7.Test Specimen Preparation7.1 Collect vitreous glass enamel or glass enamel fritparticles within the 60 to 200 mesh particle size range andcombine with 0.5 to 1.0 weight%of the hydroxypropylcell
11、ulose solution.7.2 Using the die in 4.1 and the hydraulic press in 4.2,pressthe powder prepared in 7.1 at 34 MPa(5000 psi)into a barconsistent with the dimensional guidelines found in TestMethod E228.7.3 Fire and anneal the test specimen prepared in 7.2 usinga time/temperature cycle consistent with
12、that used commer-cially for the vitreous glass enamel or glass enamel fritinvolved.1This practice is under the jurisdiction of ASTM Committee C14 on Glass andGlass Products and is the direct responsibility of Subcommittee C14.10 on GlassDecoration.Current edition approved May 1,2015.Published May 20
13、15.Originallyapproved in 1976.Last previous edition approved in 2010 as C824 91(2010).DOI:10.1520/C0824-91R15.2For 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 standar
14、ds Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.4 The ends of the fired test specimen shall conform to theguidelines given in Test Method E228.7.5 Measure the length of the test specimen to an
15、 accuracyof 0.1%with the test specimen at a temperature equivalent tothe temperature of the dilatometer at the initiation of the testprocedure(normally room temperature).ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
16、 this standard.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 every 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 I
