GOST 11739.1-90
GOST 11739.1−90 Alloys aluminium cast and wrought. Methods for determination of aluminium oxide
GOST 11739.1−90
Group B59
STATE STANDARD OF THE USSR
ALLOYS ALUMINIUM CAST AND WROUGHT
Methods for determination of aluminium oxide
Aluminium casting and wrought alloys.
Methods for determination of aluminium oxide
AXTU 1709
Valid from 01.07.91
before 01.07.96*
_______________________________
* Expiration removed by Protocol No. 5−94
The interstate Council for standardization,
Metrology and certification (I & C N 11/12, 1994). -
Note the manufacturer’s database.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR
DEVELOPERS
V. G. Davydov, doctor of engineering. Sciences; V. A. Moshkin, PhD. tech. Sciences; G. I. Friedman, PhD. tech. Sciences; V. I. Klitina, PhD. chem. Sciences
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from
3. The frequency of inspection — 5 years
4. REPLACE GOST 11739.1−78
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 61−75 |
2.2; 3.2 |
| GOST 199−78 |
2.2; 3.2 |
| GOST 3773−72 |
3.2 |
| GOST 4109−79 |
2.2 |
| GOST 4160−74 |
2.2 |
| GOST 4167−74 |
3.2 |
| GOST 4204−77 |
2.2; 3.2 |
| GOST 4328−77 |
2.2; 3.2 |
| GOST 4523−77 |
2.2 |
| GOST 7172−76 |
2.2; 3.2 |
| GOST 10484−78 |
2.2; 3.2 |
| GOST 11069−74 |
2.2; 3.2 |
| GOST 14261−77 |
2.2; 3.2 |
| GOST 18300−87 |
2.2; 3.2 |
| GOST 25086−87 |
1.1 |
| THAT 6−09−667−74 |
2.2 |
| THAT 6−09−3115−73 |
2.2; 3.2 |
| THAT 6−09−3851−75 |
2.2 |
| THAT 6−09−5077−87 |
2.2 |
| THAT 6−09−1312−81 |
2.2; 3.2 |
This standard establishes photometric methods for determination of aluminium oxide (at a total mass fraction of the surface and included aluminium oxide from 0.002 to 1.0% and the mass fraction of the included aluminum oxide from 0.002 to 0.05%, respectively) in the alloys containing up to 1% silicon.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086 with the Supplement.
1.1.1. For the results analysis be the arithmetic mean of results of two parallel measurements.
2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM OXIDE
2.1. The essence of the method
The method is based on dissolving the sample in a mixture of bromide of potassium, bromine and ethyl acetate, the separation of the undissolved alumina, the fusion of aluminum oxide with pyroterrorism potassium, dissolved water, the formation of purple-red complex of aluminum with eryhromycin-R and measuring the optical density of the solution at a wavelength of 535 nm.
2.2. Apparatus, reagents and solutions
Oven muffle.
Spectrophotometer or photoelectrocolorimeter.
a pH meter.
Bromine according to GOST 4109.
Calcium chloride, on the other 6−09−5077, svezhepoymannyh at a temperature of (500±50) °C.
Potassium bromide according to GOST 4160; dried at a temperature of (500±50) °C for 2 h, stored in desiccator over calcium chloride.
Magnesium sulfate according to GOST 4523, dehydrated by calcination at a temperature of (500±50) °C.
The methyl ester of acetic acid on the other 6−09−3851 (methyl acetate) or the ethyl ether of acetic acid (ethyl acetate) TU 6−09−667, distilled, taking the fraction of methyl acetate at a temperature (57±1) °C, the fraction of ethyl acetate at temperature (77±1) °C. In the flask with distilled ether make patronchiki of filter paper with anhydrous magnesium sulfate, and close tightly ground stopper.
The reaction mixture was: 65 cmof methyl acetate (ethyl acetate) was added 1,8−2,0 g of potassium bromide and 7 cm
of bromine (dissolved sample weight of 1 g).
The reaction mixture for washing the filters prepared as a mixture of the reaction but from reagents without special drying; diluted with methyl acetate (ethyl acetate) in the ratio 1:10.
The technical rectified ethyl alcohol according to GOST 18300.
Hydrochloric acid according to GOST 14261 or GOST 3118, distilled in a quartz apparatus, a density of 1.19 g/cm, mortar 1:1 and 0.1 mol/DM
.
Sulfuric acid according to GOST 4204, density 1.84 g/cm, solution 0,125 mol/l
and 0.5 mol/DM
.
Hydrofluoric acid according to GOST 10484.
Potassium preservatory according to GOST 7172.
The thioglycolic acid.
Phenolphthalein, alcohol solution 1 g/DM.
Sodium hydroxide according to GOST 4328, solutions 1 mol/land 0.25 mol/DM
.
Erioration-R on the other 6−09−3115, a solution of 1 g/DM.
Sodium acetate according to GOST 199.
Acetic acid according to GOST 61, a density of 1.07 g/cm.
Ammonium acetate on the other 6−09−1312.
Buffer solution pH 6: 46 g ammonium acetate and 18 g of sodium acetate were placed in a glass with a capacity of 500 cm, is dissolved in water, transferred into a measuring flask with volume capacity of 1000 cm
, made up solution to the mark with water and mix. Set the pH of the solution on the pH meter, adding, if necessary, a sodium hydroxide solution 1 mol/DM
or acetic acid.
Aluminum brand А999 according to GOST 11069*.
_______________
* On the territory of the Russian GOST 11069−2001, here and hereafter. — Note the manufacturer’s database.
Standard solutions of aluminium:
Solution a: 1 g of aluminum is placed in a beaker with a capacity of 300 cm, 100 cm pour the
hydrochloric acid solution of 1:1, cover with a watch glass and dissolve with a moderate heat, maintaining a constant volume of the same acid. The solution was transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.001 g of aluminium.
Solution B (freshly made): 1 cmof solution A is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof solution B contains 0,00001 g
aluminium.
2.3. Preparation for assay
2.3.1. In determining the amount of surface and included aluminium oxide sample weight 1−2 g is used without special treatment.
2.3.2. Included in the determination of aluminum oxide using the sample plate with a weight of 1−1,5 g. Before the analysis, the plate is cleaned with a file from captivity, the formed surface oxide and stored until weighing in buxa under a layer of ethyl alcohol (25−30 cm).
2.4. Analysis
2.4.1. A portion of the sample prepared according to claim 2.3.1 or claim 2.3.2 (cleaned the sample before weighing dried from alcohol filter paper) was placed in a flask with a capacity of 250 cmwith a reflux condenser, in which pre-reaction mixture at the rate of 70 cm
per 1 g of the sample.
The dissolution is conducted at room temperature and at slowing the dissolution by heating on a sand bath (temperature 10−15 °C below the boiling point of the corresponding ester).
The dissolution of the powder materials are initially, upon cooling, preventing a violent reaction.
After the apparent dissolution of the sample into a flask add 5 cmof the reaction mixture and continue the dissolve in low heat for 10−15 min.
2.4.2. After dissolution of the sample solution was immediately filtered through a double thick filter (the"blue ribbon"), pre-wetted with the reaction mixture.
At the end of the filter flask from under the sample solution and the filter residue is washed once 20−25 cmof the reaction mixture (you can also use the reaction mixture of reagents without special drying), and then three times with a mixture for washing the filters and then with ether until the disappearance of the brown color filters.
In the case of determining the included aluminium oxide filter is further washed five times with hydrochloric acid 0.1 mol/DMand 4−5 times with warm water.
The filter with precipitate was placed in a platinum crucible, dried, incinerated and calcined for 40 minutes at 600−700 °C.
The precipitate of aluminum oxide in a platinum crucible moisten with 2 drops of sulfuric acid, add 0.5−1.0 cmhydrofluoric acid, heated to completion of allocation of steams of sulfuric acid and the dry residue is calcined at 600−700 °C for 5−6 min.
To the thus treated precipitate add 3 drops of sulfuric acid, 1 g of potassium peacemaking and carry out fusion in a muffle furnace at a temperature of 700−800 °C for 2−3 min.
The crucible with the obtained melt is washed from the outer side of the hot 70−80 °C water, wiped with filter paper, placed in a beaker with a capacity of 200 cm, 50−70 cm pour
boiling water acidified with sulphuric acid (2.5 cm.
of sulfuric acid in 100 cm
of water) and boil until complete dissolution of water.
The resulting solution was transferred to volumetric flask with a capacity of 100 cm, made up to the mark with water and mix
T.
2.4.3. Aliquot part of the solution according to the table.1 taken in a volumetric flask with a capacity of 100 cm, top up to 50 cm
with water, add 1−2 drops of thioglycolic acid, 2 drops of phenolphthalein solution was stirred and neutralized with sodium hydroxide, using first a sodium hydroxide solution 1 mol/DM
, then 0.25 mol/DM
before the appearance of pale pink color which should disappear after adding one drop of sulfuric acid solution of 0.125 mol/DM
. Then the flask make four drops of the sulfuric acid solution of 0.5 mol/DM
solution to pH 5,6−6,0, 15 cm
of a solution of erioglaucine-R and mix. After 20 minutes add in the flask 20 cm
buffer solution, made up to the mark with water and mix.
Table 1
| Mass fraction of aluminum oxide, % |
Aliquota part of the solution, see |
| From 0.002 to 0.01 incl. |
50 |
| SV. The 0.01 «to 0.05 « |
10 |
| «To 0.05» to 0.25 « |
2 |
| «Of 0.25» to 1.0 « |
0,5 |
2.4.4. Optical density of the solution is measured at a wavelength of 535 nm in a cuvette with a layer thickness of 50 mm.
Solution comparison is water with the addition of all reagents according to claim
2.4.5. The solutions of the two control experiments is prepared as follows: filtrate after separation of the precipitate of aluminum oxide from the solution of the investigated samples immediately filtered through a double filter («blue ribbon»), pre-wetted with the reaction mixture, and further arrive at PP.2.4.2, 2.4.3,
The average value of optical density of solutions of the two control experiments is subtracted from the optical density of the sample solution.
Mass fraction of aluminium is calculated according to the calibration schedule.
2.4.6. Construction of calibration curve
In six volumetric flasks with a capacity of 100 cmpour 40−50 cm
of water, then five of the tubes add 0,5; 1,0; 1,5; 2,0; 2,5 cm
standard solution B, which corresponds to 0,000005; 0,00001; 0,000015; 0,00002; 0,000025 g of aluminum.
To the resulting solution add all the necessary reagents according to claim 2.4.3 and measure the optical density according to claim
Solution comparison is the solution not containing aluminum.
According to the obtained values of optical density of the solutions and their corresponding masses of aluminium to build the calibration graph.
2.5. Processing of the results
2.5.1. Mass fraction of aluminum oxide in percent is calculated by the formula
where is the mass of aluminum was found in the calibration schedule g;
— the weight of the portion of the sample in aliquote part of the solution, g;
Of 1.89 — ratio in terms of oxide of aluminium.
2.5.2. Discrepancies in the results must not exceed the values given in table.2.
Table 2
| Mass fraction of aluminum oxide, % |
The absolute allowable difference, % | |
| results of parallel measurements |
the results of the analysis | |
| From 0.002 to 0.005 incl. |
0,001 |
0,002 |
| SV. 0,005 «0,010 « |
0,002 |
0,003 |
| «0,010» 0,020 « |
0,004 |
0,005 |
| «0,020» 0,050 « |
0,008 |
0,01 |
| «0,05» 0,10 « |
0,02 |
0,03 |
| «To 0.10» to 0.25 « |
0,03 |
0,04 |
| «0,25» 0,50 « |
0,04 |
0,06 |
| «0,50» 1,00 « |
0,06 |
0,08 |
3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM OXIDE
3.1. The essence of the method
The method is based on dissolving the sample in a mixture of solutions of copper dichloride and ammonium chloride, the separation of the undissolved alumina, the fusion of aluminum oxide with pyroterrorism potassium, dissolved water, the formation of purple-red complex of aluminum with eryhromycin-R and measurement of optical density at a wavelength of 535 nm.
3.2. Apparatus, reagents and solutions
Oven muffle.
Spectrophotometer or photoelectrocolorimeter.
Copper dichloride 2-water according to GOST 4167.
Ammonium chloride according to GOST 3773, solution: 300 g of ammonium chloride are dissolved in 800 cmof water during heating.
The reaction mixture of 1500 g of dichloride of copper dissolved in 2200 cmof water during heating; 300 g of ammonium chloride are dissolved with heating in 800 cm
of water; the solutions were poured together and, if necessary, the mixture of the solutions filtered.
The technical rectified ethyl alcohol according to GOST 18300.
Hydrochloric acid according to GOST 14261 or GOST 3118, distilled in a quartz apparatus, a density of 1.19 g/cm, mortar 1:1 and 0.1 mol/DM
.
Sulfuric acid according to GOST 4204, density 1.84 g/cm, the solutions of 0.5 mol/l
and 0.25 mol/DM
.
Hydrofluoric acid according to GOST 10484.
Potassium preservatory according to GOST 7172.
The thioglycolic acid.
Phenolphthalein, alcohol solution 1 g/DM.
Sodium hydroxide according to GOST 4328, solutions 1 mol/land 0.25 mol/DM
.
Erioration-R on the other 6−09−3115, a solution of 1 g/DM.
Ammonium acetate on the other 6−09−1312.
Sodium acetate according to GOST 199.
Acetic acid according to GOST 61, a density of 1.07 g/cm.
Buffer solution pH 6: 46 g ammonium acetate and 18 g of sodium acetate were placed in a glass with a capacity of 500 cm, is dissolved in water, transfer the solution into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix. Set the pH of the solution on the pH meter, adding, if necessary, a sodium hydroxide solution 1 mol/DM
or acetic acid.
Aluminum brand А999 according to GOST 11069.
Standard solutions of aluminium.
Solution a: 1 g of aluminum is placed in a beaker with a capacity of 300 cm, 100 cm pour the
hydrochloric acid solution of 1:1, cover with a watch glass and dissolve with a moderate heat, maintaining a constant volume of the same solution of hydrochloric acid. The solution was transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmstandard solution contains 0.001 g of aluminium.
Solution B (freshly made): 1 cmof solution A is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof solution B has the 0.00001 g of aluminum
.
3.3. Analysis
3.3.1. A sample prepared according to claim 2.3.2, remove from the ethanol, quickly dried with filter paper, weighed, placed in a conical flask with a capacity of 250 cm, which is pre-recorded 50−70 cm
of the reaction mixture, and heated in the oven (70−90 °C).
In case of incomplete dissolution of the sample adds an additional 20 cmof the reaction mixture and then 20 cm
of a solution of ammonium chloride.
3.3.2. Upon dissolution of the sample solution was filtered through a double thick filter (the"blue ribbon»), previously moistened with hot water and a hot solution of ammonium chloride.
Filter the precipitate of aluminum oxide is washed first with hot solution of ammonium chloride until the disappearance of the green color filter, and then 5−6 times with hydrochloric acid 0.1 mol/DMand 5−6 times with warm water, paying particular attention to the edges of the filter.
The filter with precipitate was placed in a platinum crucible, dried, incinerated and calcined at a temperature of 600−700 °C for 40 min.
The residue in the platinum crucible, moistened with two drops of sulfuric acid, add 0.5−1 cmhydrofluoric acid and heated until completion of allocation of steams of sulfuric acid, after which the crucible is calcined at 600−700 °C for 5−7 min.
To the thus treated precipitate is added three drops of concentrated sulfuric acid, 1 g of potassium peacemaking and carry out fusion in the muffle at a temperature of 700−800 °C for 2−3 min.
The crucible with the obtained melt is washed with the external side of the hot water, wiped with filter paper, placed in a beaker with a capacity of 200 cm, 60−70 cm pour
boiling water acidified with sulphuric acid (2.5 cm.
of concentrated sulfuric acid in 100 cm
of water), and boil until dissolved with.
The resulting solution was transferred to volumetric flask with a capacity of 100 cm, made up to the mark with water and mix
.
3.3.3. Aliquot part of the solution according to the table.1 taken in a volumetric flask with a capacity of 100 cmand then carry out operations according to claim
3.3.4. Measurement of the optical density of the solution is carried out according to claim
3.3.5. The solutions of the two control experiments is prepared as follows: hot filtrate after separation of the precipitate of alumina was filtered through a double filter («blue ribbon»), previously moistened with hot water and a hot solution of ammonium chloride.
Washing of the filter, flowing the sludge and the preparation of the solution is carried out according to claim
The average value of optical density of solutions of the two control experiments is subtracted from the optical density of the sample solution.
Mass fraction of aluminium is calculated according to the calibration schedule.
3.3.6. For construction of calibration curve six volumetric flasks with a capacity of 100 cmpour 40−50 cm
of water, then five of the tubes add 0,5; 1,0; 1,5; 2,0; 2,5 cm
of a standard solution of aluminium Used, which corresponds to 0,000005; 0,00001; 0,000015; 0,00002; 0,000025 g of aluminum.
To the resulting solution add all the necessary reagents according to claim 2.4.3 and measure the optical density according to claim
Solution comparison is the solution not containing aluminum.
According to the obtained values of optical density of the solutions and their corresponding masses of aluminium to build the calibration graph.
3.4. Processing of the results
3.4.1. Mass fraction of aluminum oxide in percent is calculated by the formula
where is the mass of aluminum was found in the calibration schedule g;
— the weight of the portion of the sample in aliquotes part g;
Of 1.89 — the conversion factor for aluminum oxide.
3.4.2. Discrepancies in the results must not exceed the values given in table.3.
Table 3
| Mass fraction of aluminum oxide, % |
The absolute allowable difference, % | |
| results of parallel measurements |
the results of the analysis | |
| From 0.002 to 0.005 incl. |
0,002 |
0,003 |
| SV. 0,005 to 0,010 « |
0,003 |
0,004 |
| «0,010» 0,020 « |
0,005 |
0,006 |
| «0,020» 0,050 « |
0,006 |
0,008 |
