1、Designation: C374 14 (Reapproved 2015)1Standard Test Methods forFusion Flow of Porcelain Enamel Frits (Flow-ButtonMethods)1This standard is issued under the fixed designation C374; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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.1NOTESections 3 and 8 corrected editorially in May 2015.INTRODUCTIONThis test provides a procedure to compare the fluidi
3、ty of a glass frit or a porcelain enamel powderto a standard reference material at a fixed temperature above the samples glass temperature.1. Scope1.1 These test methods cover evaluation of the relativefusion flow characteristics of samples of a given porcelainenamel frit by comparison with an estab
4、lished 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 give equallyreproducible results and provide a satisfactory basis for com-parison of fusion flow of t
5、he 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 hydraulic press.1.2.2 Test Method B employs crushed, sized particles of fritto which a bonding agent has b
6、een added. Button specimensare formed in a steel mold by hand.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does
7、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 Document2.1 ASTM Standar
8、ds:2E11 Specification for Woven Wire Test Sieve Cloth and TestSievesTEST METHOD A3. Apparatus3.1 Mortar, of hard steel, 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 st
9、eel crushing mortar.”3.2 SievesNo. 12 (1.70-mm) and No. 200 (75-m) sievesconforming to Specification E11.3.3 Hydraulic Press, capable of developing 3500-lbf(15 600 N) force (Fig. 2).3.4 Steel Mold Assembly, consisting of a die and plunger,and having an inside diameter of12 in. (12.7 mm) over itsleng
10、th 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 frit to be tested shall beobtained, mixed thoroughly, and reduced by quartering t
11、oabout 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.1These test methods are under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and are the direct responsibility of SubcommitteeB08.12 on
12、Materials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved May 1, 2015. Published May 2015. Originallyapproved in 1955. Last previous edition approved in 2014 as C374 14. DOI:10.1520/C0374-14R15E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
13、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume 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 States14.2 For wet-ground enamels
14、 the sample shall be evaporatedto dryness in an evaporation dish. After cooling, the driedenamel shall be loosened and again pulverized using a pestleand mortar or similar apparatus.4.3 Dry ground samples of frit, ready-to-use powder, orenamel powder for dry electrostatic application may also betest
15、ed.5. Test Specimen5.1 Weigh 3.5 6 0.05-g samples of the standard frit and ofthe material to be tested and thoroughly mix each of thesesamples with four or five drops of a 1 % gum arabic solution.Mold fusion button test specimens of the standard and of thesample as directed in 5.2. For dry electrost
16、atic powder samples,use four to five drops of acetone instead of the aqueous gumarabic solution.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 (Fi
17、g. 2). Force the formed button outof the mold with the plunger, taking care not to damage thebutton in any way that might change the dimensions.5.3 Dry the test specimens in a suitable oven at 212F(100C) for 1 h.NOTE 2Special care must be exercised in drying buttons formed bythis method, before firi
18、ng, in order to prevent bloating and possibleeruption of the button when first placed in 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
19、 used for the ground-coated plate is not ofcritical importance, most satisfactory results 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 min
20、imum. The groundcoat enamel used to coatthe groundcoat plate shall have a median firing 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 ra
21、ck, which shall previously have been heated tofurnace temperature, and place the entire 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 p
22、ortion ofthe fusion buttons will vary more than 65F (63C) from anyother button or portion thereof. The temperature shall approxi-mate the median firing temperature for the standard that is usedas a basis for comparison. Predetermine, by one or morepre-tests, the holding time, i. e. the time required
23、 from placingthe fusion buttons in the furnace in the horizontal position (Fig.5(a) until such time as fusion of the buttons is evident from therounded appearance of the tops of the buttons. For all tests ofthe same materials, the fusion buttons shall remain in thehorizontal position for the predete
24、rmined holding time. At theend of the holding time, release the groundcoat plate to thevertical position (Fig. 5(b) and allow the fusion buttons toflow a minimum of 50 mm, following which remove the testassembly from the furnace and allow the buttons to cool. Whenthe flow is completed, the sides of
25、the fusion buttons should beapproximately parallel; 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 thefus
26、ion flow to the nearest 1 mm for each fusion 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 sh
27、all be reported as“50/55 mm.” If the width of the test specimen is observed to1 in. = 25.4 mmFIG. 1 MortarFIG. 2 Hydraulic PressC374 14 (2015)12vary 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
28、3.1.8.2 SievesNo. 60 (250 m) and No. 200 (75 m) sievesconforming to Specification E11.8.3 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) over its length of 114 in. (31.8mm).8.4 Fusion Flow RackSee 3.5.9. S
29、ample9.1 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 hardsteel mortar to pass a No. 60 (250 m) sieve and be retained ona No. 200 (75 m) sieve. In order to avoid the excessiver
30、eduction of fines, they shall be removed frequently during theprocess of reduction by throwing the sample on the sieve andcontinuing the crushing of the coarser particles until all thesample passes through the sieve.9.2 For wet-ground enamels the sample shall be evaporatedto dryness in an evaporatio
31、n dish. After cooling, the driedMetric 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 AC374 14 (2015)13enamel shall be loosened and again pulverized using a pestleand mortar or similar apparatus.1 in. = 25.4 mmFIG. 4 Fusion
32、 Flow Rack(a) Fusion Buttons in Horizontal Position (b) Fusion Buttons in Vertical PositionFIG. 5 Fusion Test AssemblyC374 14 (2015)149.3 Dry ground samples of frit, ready-to-use powder, orenamel powder for dry electrostatic application may also betested.10. Preparation of Test Specimens10.1 Weigh 3
33、.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 standard and of the sample asdirected in 10.2.10.2 Place the mixture in the steel mold with the plunger
34、inplace and tamp the mixture to form a solid button (Note 3).Force the formed button out of the mold, taking care not todamage the button in any way that might change the dimen-sions.NOTE 3Since the height of the button will generally be controlled bythe density of the material, for materials of app
35、roximately 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 materials of the same density and tamp thepowder to this mark each time a button is formed.10.3 Dry the tes
36、t specimens (Note 2).11. Procedure11.1 Mount 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 7.13. Precision and Bias13.1 No statement is made for precision or bias of these testmethods because the results
37、are used to compare the relativefusion flow characteristics of a given porcelain enamel frit,with those of an established standard to determine anticipatedperformance.14. Keywords14.1 comparative test; fusion flow; glass coating; moltenflow; porcelain enamel frits1 in. = 25.4 mmFIG. 6 Details of Mol
38、d for Test SpecimensTest Method BC374 14 (2015)15ASTM 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 of the validity of any such patent rights
39、, 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 re
40、vision 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 comments have not received a fair hearing yo
41、u 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 or multiple copies) of this standard may be
42、 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 14 (2015)16
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