1、Designation: C 374 70 (Reapproved 2004)e1Standard Test Methods forFusion Flow of Porcelain Enamel Frits (Flow-ButtonMethods)1This standard is issued under the fixed designation C 374; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEKeywords were added editorially in September 2004.1. Scope1.1 These test methods cover evaluation of the relat
3、ivefusion flow characteristics of samples of a given porcelainenamel frit by comparison with an established standard for thatfrit.1.2 Two test methods are included, differing only in certaindetails of the samples and in the apparatus and procedure forpreparation of test specimens. Both test methods
4、give equallyreproducible results and provide a satisfactory basis for com-parison of fusion flow of the sample with that of the establishedstandard.1.2.1 Test Method A employs granular particles of frit towhich a bonding agent has been added. Button specimens areformed under high pressure in a hydra
5、ulic press.1.2.2 Test Method B employs crushed, sized particles of fritto which a bonding agent has been added. Button specimensare formed in a steel mold by hand.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
6、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 Document2.1 ASTM Standards:2E 11 Specification for Wire-Cloth Sieves for Testing Pur-posesTEST METHOD A3. Apparatus3.1 Mortar, of hard ste
7、el, resistant to abrasion by theporcelain enamel frit, and conforming to the dimensions shownin Fig. 1.NOTE 1Suitable mortars are available commercially under the desig-nation “tool steel crushing mortar.”3.2 SievesNo. 12 (1.70-mm) and No. 200 (75-m) sievesconforming to Specification E 11.NOTE 2Tyle
8、r Standard Series sieves No. 12 (0.0060-in. (0.152-mm)openings) and No. 200 (0.029-in. (0.07-mm) openings) correspond toASTM sieves Nos. 12 and 200 (U.S. Standard Sieves series numbers).3.3 Hydraulic Press, capable of developing 3500-lbf(15 600 N) force (Fig. 2).3.4 Steel Mold Assembly, consisting o
9、f a die and plunger,and having an inside diameter of12 in. (12.7 mm) over itslength of 218 in. (54 mm) as illustrated in Fig. 3.3.5 Fusion Flow Rack, preferably constructed of heat-resisting alloy and conforming to the detailed requirementsshown in Fig. 4.4. Sample4.1 A representative sample of the
10、frit to be tested shall beobtained, mixed thoroughly, and reduced by quartering toabout 25 g. This sample shall be crushed in a hard steel mortarto pass a No. 12 (1.70-mm) sieve and be retained on a No. 200(75-m) sieve.5. Test Specimen5.1 Weigh 3.5 6 0.05-g samples of the standard frit and ofthe mat
11、erial to be tested and thoroughly mix each of thesesamples with 4 or 5 drops of a 1 % gum arabic solution. Moldfusion button test specimens of the standard and of the sampleas directed in 5.2.1These test methods are under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and a
12、re the direct responsibility of SubcommitteeB08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved Aug. 1, 2004. Published September 2004. Originallyapproved in 1955. Last previous edition approved in 1998 as C 374 70 (1998).2For referenced ASTM standards, visit
13、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
14、, United States.5.2 Place the sample in the steel mold. Place the moldassembly containing the sample in a hydraulic press and bringthe press up to 3000 to 3500 lbf (13.3 to 15.6 kN) total load,and immediately release (Fig. 2). Force the formed button outof the mold with the plunger, taking care not
15、to damage thebutton in any way that might change the dimensions.5.3 Dry the test specimens in a suitable oven at 100C for 1h.NOTE 3Special care must be exercised in drying buttons formed bythis method, before firing, in order to prevent bloating and possibleeruption of the button when first placed i
16、n the furnace.6. Procedure6.1 MountingPlace the dried fusion buttons on a firedgroundcoat plate. The location of the test specimens withrespect to the standard may be modified as desired. Althoughthe gage of metal used for the ground-coated plate is not ofcritical importance, most satisfactory resul
17、ts will be obtainedwhen the metal is not heavier than 18 gage nor lighter than 22gage (1.02 to 0.044 mm). Use the same gage of metalconsistently from test to test in order to reduce the number ofvariables to a minimum. The groundcoat enamel used to coatthe groundcoat plate shall have a median firing
18、 temperature nomore than 50F (28C) below the median firing temperature forthe most refractory frit being tested. Place the groundcoat platewith fusion buttons in place in a horizontal position on thefusion flow rack, which shall previously have been heated tofurnace temperature, and place the entire
19、 test assembly in thefurnace immediately.6.2 FiringFire in a furnace in which the atmosphere isoxidizing and entirely free of any products of combustion. Heatdistribution within the furnace shall be such that no portion ofthe fusion buttons will vary more than 65F (63C) from anyother button or porti
20、on thereof. The temperature shall approxi-mate the median firing temperature for the standard that is usedas a basis for comparison. Allow the buttons to remain in thehorizontal position (Fig. 5(a) until such time as fusion of thebuttons is evident from the rounded appearance of the tops ofthe butto
21、ns. Then release the groundcoat plate to the verticalposition (Fig. 5(b) and allow the fusion buttons to flow aminimum of 50 mm, following which remove the test assemblyfrom the furnace and allow the buttons to cool. When the flowis completed, the sides of the fusion buttons should beapproximately p
22、arallel; that is, there should be no excessivespreading of the fusion buttons in the horizontal position,indicating that the buttons were allowed to remain in thehorizontal position for too long a time.6.3 Measuring FlowMeasure the greatest length of thefusion flow to the nearest 1 mm for each fusio
23、n button,including the standard.7. Report7.1 Report the length of the fusion flow for each testspecimen in comparison with the standard run at the same time.For example, if a given specimen flows 50 mm against a flowfor the standard of 55 mm, the results shall be reported as“50/55 mm.” If the width
24、of the test specimen is observed tovary more than 10 % from the width of the standard, length-times-width values shall be calculated for the comparison.TEST METHOD B8. Apparatus8.1 MortarSee 3.1.8.2 SievesNo. 60 (250-m) and No. 200 (75-m) sievesconforming to Specification E 11.NOTE 4Tyler Standard S
25、eries sieves No. 60 (0.0097-in. openings) andNo. 200 (0.0029-in. openings) correspond to ASTM sieves Nos. 60 and200 (U.S. Standard Sieve series numbers).8.3 Steel Mold Assembly, consisting of a die, plunger, andbackup disk as shown in Fig. 6. The inside diameter of themold shall be12 in. (12.7 mm) o
26、ver its length of 114 in. (31.8mm).8.4 Fusion Flow RackSee 3.5.9. Sample9.1 A representative sample of the frit to be tested shall beobtained, mixed thoroughly, and reduced by quartering toabout 25 g. This sample shall be crushed by impact in a hardNOTE1 in. = 25.4 mm.FIG. 1 MortarFIG. 2 Hydraulic P
27、ressC 374 70 (2004)e12steel mortar to pass a No. 60 (250-m) sieve and be retained ona No. 200 (75-m) sieve. In order to avoid the excessivereduction of fines, they shall be removed frequently during theprocess of reduction by throwing the sample on the sieve andcontinuing the crushing of the coarser
28、 particles until all thesample passes through the sieve.10. Preparation of Test Specimens10.1 Weigh 3.5 6 0.05-g samples of the standard and of thematerial to be tested and thoroughly mix each of these sampleswith 4 or 5 drops of a 1 % gum arabic solution. Mold fusionbutton test specimens of the sta
29、ndard and of the sample asdirected in 10.2.10.2 Place the mixture in the steel mold with the plunger inplace and tamp the mixture to form a solid button (Note 5).Force the formed button out of the mold, taking care not todamage the button in any way that might change the dimen-sions.NOTE 5Since the
30、height of the button will generally be controlled bythe density of the material, for materials of approximately the samedensity such as leadless frits or lead-bearing frits, it will be foundconvenient to score the side of the plunger at a point representing theaverage height of the button for materi
31、als of the same density and tamp thepowder to this mark each time a button is formed.10.3 Dry the test specimens (Note 3).NOTEMetric Equivalentin. mm in. mm0.010 0.0338 9.5 134 44.01332 10.3 218 54.012 12.7 212 63.5FIG. 3 Mold for Test SpecimensTest Method AC 374 70 (2004)e1311. Procedure11.1 Mount
32、and fire the fusion buttons and measure the flowas directed in Section 6.12. Report12.1 Report the results of the test as directed in Section 7.NOTEin. = 25.4 mm.FIG. 4 Fusion Flow RackNOTE(a) Fusion Buttons in Horizontal Position (b) Fusion Buttons in Vertical PositionFIG. 5 Fusion Test AssemblyC 3
33、74 70 (2004)e1413. Precision and Accuracy13.1 No statement is made for precision or accuracy of thismethod because the results are used to compare the relativefusion flow characteristics of a given porcelain enamel frit,with those of an established standard to determine anticipatedperformance.14. Ke
34、ywords14.1 comparative test; fusion flow; glass coating; moltenflow; porcelain enamel fritsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination
35、 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 withdraw
36、n. 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 technical committee, which you may attend. If you feel that your co
37、mments 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 Conshohocken, PA 19428-2959,United States. Individual reprints (single o
38、r 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).NOTEin. = 25.4 mm.FIG. 6 Details of Mold for Test SpecimensTest Method BC 374 70 (2004)e15
