1、Designation: D6906 12a (Reapproved 2016)Standard Test Method forDetermination of Titanium Treatment Weight on MetalSubstrates by Wavelength Dispersive X-Ray Fluorescence1This standard is issued under the fixed designation D6906; the number immediately following the designation indicates the year ofo
2、riginal 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 use of wavelength disper-sive X-
3、ray fluorescence (WDXRF) techniques for determina-tion of the coating weight of titanium treatments on metalsubstrates. These techniques are applicable for determinationof the coating weight as titanium or total coating weight of atitanium containing treatment, or both, on a variety of metalsubstrat
4、es.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. Reference
5、d Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Summary of Practice3.1 ExcitationThe measurement of titanium treatmentcoating weights by WDXRF me
6、thods is based on the combinedinteraction of the titanium coating and the substrate with anintense beam of primary radiation. Since each element fluo-resces at an energy characteristic of the particular element, thisinteraction results in the generation of X-rays of definedenergy. The primary radiat
7、ion may be generated by an X-raytube or derived from a radioisotope.3.2 DetectionThe secondary beam (fluorescent X-rays ofthe elements and scattered radiation) is read by a detector thatcan discriminate between the energy levels of fluorescingradiations in the secondary beam. The detection system in
8、-cludes the radiation detector with electronics for pulse ampli-fication and pulse counting.3.3 Basic Principle:3.3.1 A relationship exists between the treatment coatingweight and secondary radiation intensity. This relationship isusually linear within the desired coating weights of thetitanium trea
9、tments on metal substrates. The measurements arebased on primary standards of known coating weights andinstrument calibration that correlates the secondary radiationintensity with the coating weight quantitatively.3.3.2 The coating weight is determined by measurement ofthe fluorescent X-rays of the
10、coating. The detection system isset to count the number of X-rays in an energy region that ischaracteristic of X-rays from the element of interest. Theelement of interest in this practice is titanium.3.3.3 If a linear relationship exists, the coating weight andnumber of counts of X-rays of a titaniu
11、m treatment on aparticular substrate can be expressed by a conversion factorthat represents the number of counts for a particular coatingweight unit/unit area. This is usually expressed in mg/ft2ormg/m2of titanium or total coating weight.3.3.4 The exact relationship between the measured numberof cou
12、nts and the corresponding coating weight must beestablished for each individual combination of substrate andtitanium-containing treatment. Usually determined by the treat-ment supplier, this relationship is established by using primarystandards having known amounts of the same treatment appliedto th
13、e same substrate composition as the specimens to bemeasured.3.3.5 Some X-ray apparatuses have a data handling systemwhereby a coating weight versus X-ray counts curve may beestablished within the system for the direct readout of coatingweight. If such apparatus does not permit the entry of aconversi
14、on factor as described in 3.3.3, it is calibrated using abare, untreated specimen and a minimum of three specimenswith known coating weights of the treatment and substratecombination of interest. The coating weight to be measuredmust be within the range of these known coating weights. Morethan three
15、 known specimens must be used if the relationship ofX-ray counts to coating weight is not linear over the range to1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.53 on Coil
16、 Coated Metal.Current edition approved Dec. 1, 2016. Published December 2016. Originallyapproved in 2003. Last previous edition approved in 2012 as D6906 12a. DOI:10.1520/D6906-12AR16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm
17、.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 StatesThis international standard was developed in accordance with int
18、ernationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1be measured. The treatment supplier should be
19、consulted forrecommendations for establishing the curve in the instrumentfor the particular treatment and substrate combination ofinterest.4. Significance and Use4.1 The procedure described in this test method is designedto provide a method by which the coating weight of titaniumtreatments on metal
20、substrates may be determined.4.2 This test method is applicable for determination of thetotal coating weight and the titanium coating weight of atitanium-containing treatment.5. Apparatus and Materials5.1 Measuring Instrument, which is capable of determiningthe coating weights of titanium-containing
21、 treatments on metalsubstrates by X-ray fluorescence is required. The treatmentsupplier should be consulted for the suitability of the instru-mentation to be used5.2 Calibration Standard, necessary to calibrate the instru-ment. The count value of this standard must be specified by thetreatment suppl
22、ier.5.3 Treated Coupon, on which the coating weight is to bedetermined must be cut to the required size for the instrumentfrom the treated substrate.5.4 Blank (Bare and Untreated) Coupon should be a sampleof the same metal substrate on which the treatment coatingweight is to be determined. It may be
23、 necessary to prepare ablank coupon from a treated sample if an untreated coupon isnot available. To best imitate a bare, untreated blank, abrade atreated coupon that is from the same metal specimen as the testspecimen using a small abrasive pad.5.4.1 The first abrading is made parallel with the rol
24、lingdirection of the metal, the second abrading is made perpen-dicular to the rolling direction of the metal, and the thirdabrading is made parallel with the rolling direction of themetal. This procedure should be repeated until constant read-ings are obtained. Always use the same side of the metals
25、ubstrate from which the readings of the treated coupon will betaken.6. Test Specimens6.1 All test specimens must be flat in the area of measure-ment and free of burrs and distortions that would preventproper seating in the specimen holder.6.2 The treatment on the substrate must be uniform in thearea
26、 of measurement.6.3 The area of measurement must be maintained free offoreign materials. The specimen must be handled only by theedges that are outside of the area to be measured.6.4 The coated area of the specimen must be larger than themeasuring area.7. Procedure7.1 Operate the instrument in accor
27、dance with the manufac-turers instructions.7.2 Set the instrument settings as follows:Dial and arm titanium positionSeconds indicator pretreatment supplierMultiplier switch pretreatment supplierResponse switch pretreatment supplierRange pretreatment supplierMilliamps adjust for calibration of output
28、pretreatment supplier7.3 All specimens must be seated firmly and securely overthe measuring opening. The distance between the measuringapparatus and specimen must be maintained the same as thatduring the calibration. The blank and treated specimens mustbe placed in the holder so that the rolling dir
29、ection of the metalis in the same orientation. Whenever a sample tray holder is apart of the apparatus, the same opening of the slide must beused for the blank and treated specimen unless the openingshave been determined to produce equivalent results. If it isnecessary to use a backer to hold the te
30、st specimen firmlyagainst the window, make sure that the backer is of untreatedcoupons of the same metal as the specimen. The same backermust be used for each set of measurements.7.4 Insert the titanium calibration standard that has beenrecommended by the treatment supplier into the instrument,and o
31、btain a count. Adjust the current with the control knob onthe probe until the count value is within a single significantfigure rounded approximation of 63 times the square root ofthe counts provided by the treatment supplier with eachtitanium calibration standard.7.5 Obtain the counts of a blank.7.6
32、 Obtain the counts of the treated specimen.7.7 Consult the instrument manufacturers instructionmanuals for calibrating and operating procedures if the X-rayapparatus has a data handling system for direct readout ofcoating weights.8. Calculation8.1 Use 8.2 8.5 for calculating the coating weight if an
33、automated data handling system is not available.8.2 The average of a minimum of three readings of both theblank and treated specimen is used to calculate the coatingweight.8.3 Calculate the delta () counts by subtracting the countsof the blank from the counts of the treated specimen.8.4 The coating
34、weight is calculated by dividing the counts by the conversion factor that is supplied by thetreatment supplier for the particular substrate and treatmentcombination under study.Coating weight weight/unit area! 5 countsconversion factor(1)Other methods as recommended by the treatment suppliermay be u
35、sed to calculate the coating weight.8.5 The conversion factors supplied by the treatment sup-plier are valid only for the instrument calibration procedurerecommended by the treatment supplier.D6906 12a (2016)29. Precision and Bias9.1 The precision of this test method is based on aninterlaboratory st
36、udy of D6906, Standard Test Method forDetermination of Titanium Treatment Weight on Metal Sub-strates by Wavelength Dispersive X-Ray Fluorescence con-ducted in 2011. A total of eleven laboratories tested samplesprepared on three different representative coil industry metalsubstrates, each substrate
37、having been coated with threedifferent target coating weights (low, intermediate, and high) ofeither of two different Ti-containing commercial coil dry-in-place metal pretreatments. Each laboratory reported test resultsfrom triplicate samples made for each substrate/pretreatment/coating weight varia
38、tion in this study. Every test result was theaverage of triplicate measurements made to determine the net(Sample Blank) WDXRF integrated Ti signal intensities of aparticular sample, presumed to be proportional to its respectivepretreatment coating weight. Practice E691 was followed forthe design and
39、 analysis of the data; the details are given inASTM Research Report No. RR:D01-1167.39.1.1 Repeatability Limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material; “r”istheinterval representing the critical diffe
40、rence between two testresults for the same pretreatment/substrate combination at thesame intended applied coating weight, obtained by the sameoperator using the same equipment on the same day in the samelaboratory.9.1.1.1 Repeatability limits are listed in Table 1.9.1.2 Reproducibility Limit (R)Two
41、test results shall bejudged not equivalent if they differ by more than the “R” valuefor that material; “R” is the interval representing the criticaldifference between two test results for the same pretreatment/substrate combination at the same intended applied coatingweight, obtained by different op
42、erators using different equip-ment in different laboratories.9.1.2.1 Reproducibility limits are listed in Table 1.9.1.3 The above terms (repeatability limit and reproducibil-ity limit) are used as specified in Practice E177.9.1.4 Any judgment in accordance with statements 9.1.1and 9.1.2 would have a
43、n approximate 95 % probability ofbeing correct.9.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.9.3 The precision statement was determined through statis-tical examination of
44、295 results, from a total of elevenlaboratories, on three substrates, with three applied pretreat-ment target coating weights. The coating weight targets weredesignated in the study as:A: Low target coating weightB: Intermediate target coating weightC: High target coating weight10. Keywords10.1 coat
45、ing weight; non-chrome; titanium; treatment;X-ray fluorescence3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1167. ContactASTM CustomerService at serviceastm.org.TABLE 1 Net Integrated Ti Signal Intensity (Counts)MaterialAv
46、erageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitXsrsRrRAl Bare A 455.42 60.37 71.08 169.04 199.03Al Bare B 678.76 55.69 71.97 155.94 201.53Al Bare C 863.99 44.30 83.50 124.03 233.81Galvalume Bare A 443.09 85.97 109.86 240.71 307.62Galvalume B
47、are B 651.77 93.14 128.89 260.78 360.90Galvalume Bare C 836.00 92.81 133.00 259.86 372.40HDG Bare A 198.34 89.19 109.30 249.73 306.03HDG Bare B 381.63 125.40 137.87 351.12 386.03HDG Bare C 318.95 93.91 105.65 262.95 295.83AThe average of the laboratories calculated averages.D6906 12a (2016)3ASTM Int
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49、y 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 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 you shouldmake your views kn
