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1、INTERNATIONAL STANDARD IS0 11433 First edition 1993-09-I 5 Nickel alloys - Determination of titanium content - Diantipyrylmethane molecular absorption spectrometric method Alliages de nickel - Dosage du titane - MBthode par spectrom;is;r of 0,02 ml, in accordance with IS0 385-1, 5.5 Molecular absorp
2、tion spectrometer, capable of measuring absorbance at a wavelength of 390 nm. 6 Sampling and sample preparation 6.1 Sampling and preparation of the laboratory sample shall be carried out by normal agreed pro- cedures or, in the case of dispute, according to the relevant International Standard. 6.2 T
3、he laboratory sample is normally in the form of millings or drillings and no further preparation of the sample is necessary. 2 6.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high-purity ac
4、etone and dried in air. 6.4 If the laboratory sample contains particles or pieces of widely varying sizes, the test sample should be obtained by riffling. 7 Procedure 7.1 Preparation of test solution 7.1.1 Test portion Weigh, to the nearest 0,l mg, a test portion of the sample according to table 1.
5、Table 1 - Mass of sample to be taken I I I Expected titanium content % (m/m) Mass of sample 9 0,3 to 3,0 0,lS to 0,21 7.1.2 Dissolution of a test portion in acid Transfer the test portion to the 125 ml conical beaker (5.1). Add 10 ml of the hydrochloric acid (4.1) and 3 ml of the nitric acid (4.4).
6、Apply sufficient heat to initiate and maintain the reaction until dissolution is complete. If the alloy resists dissolution, some ad- justment of the acid mixture may be required. Add hydrochloric acid (4.1) in 1 ml increments and con- tinue heating to dissolve the test portion. 7.1.3 Preparation of
7、 the final test solution Add 7 ml of the dilute sulfuric acid (4.3) and evaporate the solution until heavy white fumes appear. Cool the contents and proceed as directed in 7.1.3.1 or 7.1.3.2, depending on whether tantalum is present or not. 7.1.3.1 In the absence of tantalum add 20 ml of the oxalic
8、acid solution (4.8) and heat to dissolve the salts. Cool the solution and, in tungsten-free alloys, proceed as directed in 7.1.4. 7.1.3.1.1 If the alloy contains tungsten, add suf- ficient ammonium hydroxide solution (4.5) to make the solution alkaline. Boil the solution until the tungstic acid is d
9、issolved. Cool the solution and re- acidify by adding 20 ml of the hydrochloric acid (4.1). Cool the solution and proceed as directed in 7.1.4. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resal
10、e, 04/27/2007 03:53:08 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11433:1993(E) 7.1.3.2 In the presence of tantalum add 30 ml of water, heat to dissolve the salts and cool again. Filter the solution through a tightly packed filter pulp pad. Wash the precipitate wit
11、h warm water. Retain the filtrate. Transfer the pad and precipitate to a platinum crucible. Ignite at 800 “C and cool. Add 1 g of the potassium hydrogen sulfate (4.61, cover the crucible with a platinum lid, and fuse carefully over a flame. Cool and transfer the crucible to a 150 ml beaker containin
12、g 20 ml of the oxalic acid solution (4.8). Heat carefully until the melt is dissolved. Wash and remove the platinum crucible. Combine the oxalate solution with the original filtrate and proceed as directed in 7.1.4. 7.1.4 Dilutions 7.1.4.1 Dilution for less than 1 % (m/m) titanium Transfer the test
13、solution (7.1.3.1 or 7.1.3.1.1 or 7.1.3.2) to a 100 ml one-mark volumetric flask (5.2), make up to the mark with water and mix. 7.1.4.2 Dilution for 1 % (m/m) to 5 % (m/m) titanium Transfer the test solution (7.1.3.1 or 7.1.3.1.1 or 7.1.3.2) to a 250 ml one-mark volumetric flask (5.21, make up to th
14、e mark with water and mix. 7.2 Colour development 7.2.1 Using a pipette (5.31, transfer 5,0 ml aliquots of the test solution (7.1.4.1 or 7.1.4.2) to each of two 50 ml one-mark volumetric flasks (5.2). 7.2.2 Add 5,0 ml of the dilute hydrochloric acid (4.2), 5,0 ml of the ascorbic acid solution (4.7)
15、and 20,O ml of the sodium chloride solution (4.10) to both volumetric flasks. Mix the solutions and allow to stand for a few minutes. 7.2.3 Add IO,0 ml of the diantipyrylmethane solution (4.9) to one of the volumetric flasks. 7.2.4 Make up the solutions in both flasks (7.2.2 and 7.2.3) to the marks
16、with water, mix and allow to stand for 40 min. 7.3 Spectrometric measurement 7.3.1 Using 1 cm cells, measure the absorbance of both solutions in 7.2.4 against water as the reference, at a wavelength of 390 nm with the molecular ab- sorption spectrometer (5.5). 7.3.2 Subtract the background absorbanc
17、e of the test solution from the absorbance of the test solution containing the diantipyrylmethane complex. 7.4 Blank test Carry out a blank test in parallel with the determi- nation, following the same procedure and using the same quantities of all the reagents. 7.5 Calibration 7.5.1 Using a microbu
18、rette (5.41, transfer 0 ml, I,0 ml, 2,0 ml, 3,0 ml, 4,0 ml and 5,0 ml of the titanium standard solution (4.12) to a series of 50 ml one-mark volumetric flasks. 7.5.2 Add the dilute hydrochloric acid, ascorbic acid and sodium chloride solutions as described in 7.2.2. 7.5.3 Add 10,O ml of the diantipy
19、rylmethane solution (4.9) to the solutions, Dilute the solutions to the marks with water and mix. Allow to stand for 40 min. This series corresponds to 0 pg, 0,5 pg, I,0 pg, 1,5 lg, 2,0 pg and 2,5 Fg of titanium per millilitre. 7.5.4 Measure the absorbance of the calibration solutions as described i
20、n 7.3. Subtract the measured absorbance of the 0 pg/ml calibration solution from the absorbance values of the remaining calibration solutions. 7.5.5 Plot the corrected absorbance values against the respective concentrations of titanium, in micro- grams per millilitre, in the calibration solutions. 7
21、.6 Number of determinations Carry out the.determination at least in duplicate. 7.7 Check test The performance of the method may be checked by analysing, in parallel with the determination and fol- lowing the same procedure, one or more samples of the same alloy type whose titanium content is known.
22、8 Expression of results 8.1 Calculation 8.1.1 Determine the concentration of titanium in the test solution (see 7.3.21, and in the blank test (7.4) by means of the calibration graph (7.5.5). 8.1.2 Calculate the titanium content Tin expressed as a percentage by mass, of the test portron using the for
23、mula = (PTi - PTi,Ojv x , o-3 I m where 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:53:08 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1
24、1433:1993(E) PTi is the titanium concentration, in micro- grams per millilitre, in the test solution (8.1 .l); PTi,O is the titanium concentration, in micro- grams per millilitre, in the blank test sol- ution (8.1 .l); V is the volume, in millilitres, of the test sol- ution (7.1.4.1 or 7.1.4.2); m i
25、s the mass, in grams, of the test portion (7.1 .l). 8.2 Precision 8.2.1 Laboratory tests Eleven laboratories in four countries participated in the testing of this procedure using four samples of nom- inal composition given in table2. Each sample was analysed in duplicate on different days. 8.2.2 Sta
26、tistical analysis 8.2.2.1 Results from the interlaboratory test pro- gramme were evaluated according to IS0 5725, using the means of the duplicate results. The data were tested for statistical outliers by the Cochran and Dixon tests given in IS0 5725. 8.2.2.2 The principle of the Cochran test is tha
27、t a set of results is an outlier if the within-laboratory variance is too large in relation to others. Dixon s test is to determine if the mean from laboratory is too far from the other laboratory means. Both tests were applied at the 95 % confidence level. 8.2.2.3 Repeatability and reproducibility
28、were calcu- lated according to IS0 5725 at the 95 % confidence level. Results of the statistical analyses are given in table 3. 8.2.2.4 One laboratory was rejected as a Cochran outlier for sample RE-1. 9 Interferences Molybdenum, if present, may cause a high bias in the reported titanium value (see
29、8.1.2) to the extent of 0,001 % (m/m) Ti for every 1,0 % (m/m) MO. 10 Test report The test report shall include the following information: a) the reference to the method used; b) the results of the analysis; c) the number of independent replications; d) any unusual features noted during the analysis
30、; e) any operation not included in this International Standard or regarded as optional. Sample Table 2 - Nominal composition of test samples % h/m) Al Co Cr Fe Hf MO Nb Ta Ti W Ni RE-1 5,5 10 9 RE-2 0,5 0,5 20 RE-3 I,9 19 22 RE-4 3,0 10 14 - 18 - - I,6 - - - - 3 - 4 - 5 1 - 2,6 - I,4 - I,5 10 I,0 -
31、3,7 2 5,0 4 Remainder Remainder Remainder Remainder Sample reference Table 3 - Results of statistical anal Mean, Within-laboratory Between-labora- % b?dnl)l standard tory standard deviation deviation RE-1 1,49 0,015 0,026 0,041 0,084 RE-2 0,37 0,007 0,012 0,019 0,038 RE-3 3,69 0,018 0,026 0,050 0,08
32、8 RE-4 5,09 0,022 0,044 0,063 0,139 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:53:08 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11433:1
33、993(E) UDC 669.245:543.422:546.22 Descriptors: nickel alloys, chemical analysis, determination of content, titanium, molecular absorption spectrometric method. Price based on 4 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:53:08 MDTNo reproduction or networking permitted without license from IHS -,-,-
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