CN112730143A - Method for measuring effective chemical components in brazing flux - Google Patents
Method for measuring effective chemical components in brazing flux Download PDFInfo
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- 230000004907 flux Effects 0.000 title claims abstract description 94
- 238000005219 brazing Methods 0.000 title claims abstract description 56
- 238000000034 method Methods 0.000 title claims abstract description 36
- 239000000126 substance Substances 0.000 title claims abstract description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 61
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 54
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- 238000005303 weighing Methods 0.000 claims abstract description 21
- 238000001816 cooling Methods 0.000 claims abstract description 17
- 238000005259 measurement Methods 0.000 claims abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 150
- 239000000523 sample Substances 0.000 claims description 69
- 239000012086 standard solution Substances 0.000 claims description 67
- 239000012085 test solution Substances 0.000 claims description 45
- 239000000243 solution Substances 0.000 claims description 41
- 238000004448 titration Methods 0.000 claims description 25
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 21
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 claims description 20
- 229910052791 calcium Inorganic materials 0.000 claims description 20
- 239000011575 calcium Substances 0.000 claims description 20
- 239000000706 filtrate Substances 0.000 claims description 17
- 238000012360 testing method Methods 0.000 claims description 17
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 16
- KJFMBFZCATUALV-UHFFFAOYSA-N phenolphthalein Chemical compound C1=CC(O)=CC=C1C1(C=2C=CC(O)=CC=2)C2=CC=CC=C2C(=O)O1 KJFMBFZCATUALV-UHFFFAOYSA-N 0.000 claims description 14
- 239000011734 sodium Substances 0.000 claims description 13
- 239000012488 sample solution Substances 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 8
- MKNQNPYGAQGARI-UHFFFAOYSA-N 4-(bromomethyl)phenol Chemical compound OC1=CC=C(CBr)C=C1 MKNQNPYGAQGARI-UHFFFAOYSA-N 0.000 claims description 7
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 7
- 230000007935 neutral effect Effects 0.000 claims description 7
- 229910052708 sodium Inorganic materials 0.000 claims description 7
- FBPFZTCFMRRESA-KVTDHHQDSA-N D-Mannitol Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-KVTDHHQDSA-N 0.000 claims description 5
- 229930195725 Mannitol Natural products 0.000 claims description 5
- 241000220317 Rosa Species 0.000 claims description 5
- 229910052796 boron Inorganic materials 0.000 claims description 5
- 229910052731 fluorine Inorganic materials 0.000 claims description 5
- 239000000594 mannitol Substances 0.000 claims description 5
- 235000010355 mannitol Nutrition 0.000 claims description 5
- ORFSSYGWXNGVFB-UHFFFAOYSA-N sodium 4-amino-6-[[4-[4-[(8-amino-1-hydroxy-5,7-disulfonaphthalen-2-yl)diazenyl]-3-methoxyphenyl]-2-methoxyphenyl]diazenyl]-5-hydroxynaphthalene-1,3-disulfonic acid Chemical compound COC1=C(C=CC(=C1)C2=CC(=C(C=C2)N=NC3=C(C4=C(C=C3)C(=CC(=C4N)S(=O)(=O)O)S(=O)(=O)O)O)OC)N=NC5=C(C6=C(C=C5)C(=CC(=C6N)S(=O)(=O)O)S(=O)(=O)O)O.[Na+] ORFSSYGWXNGVFB-UHFFFAOYSA-N 0.000 claims description 5
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 4
- 239000011737 fluorine Substances 0.000 claims description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 claims 1
- 239000004615 ingredient Substances 0.000 claims 1
- 239000007788 liquid Substances 0.000 claims 1
- 238000004458 analytical method Methods 0.000 abstract description 14
- 238000001514 detection method Methods 0.000 abstract description 12
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 abstract description 8
- 230000000007 visual effect Effects 0.000 abstract description 5
- 230000018044 dehydration Effects 0.000 abstract description 2
- 238000006297 dehydration reaction Methods 0.000 abstract description 2
- 238000000691 measurement method Methods 0.000 abstract 1
- 238000004364 calculation method Methods 0.000 description 13
- 238000005476 soldering Methods 0.000 description 12
- 239000000047 product Substances 0.000 description 11
- 238000003466 welding Methods 0.000 description 10
- 238000005516 engineering process Methods 0.000 description 8
- 239000011521 glass Substances 0.000 description 8
- 230000007123 defense Effects 0.000 description 5
- 238000011161 development Methods 0.000 description 5
- 238000009835 boiling Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 229910001634 calcium fluoride Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000013074 reference sample Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000003918 potentiometric titration Methods 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/04—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder
- G01N5/045—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder for determining moisture content
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Molecular Biology (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Plasma & Fusion (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The invention relates to a method for measuring effective chemical components in a brazing flux, and belongs to the technical field of component analysis. The method comprises collecting three parallel samples, placing one sample in a beaker, adding water, heating to dissolve the sample, separating insoluble substances, and measuring Na+、B3+Content (c); another sample is placed in a beaker and hydrochloric acid is added to dissolve the sample and measure Ca2+、F‑Content (c); and putting another sample into the crucible and placing the crucible in a muffle furnace, then heating for dehydration, finally cooling along with the furnace and weighing, and measuring the water content of the sample. The method of the invention determines the effective components in the brazing flux, the determination result is visual and accurate, whether the brazing flux can meet the use requirement can be directly determined through detection, the quality objection can be reduced, and the reliability and the stability of the product can be ensured. The measurement method of the present invention is suitable for the measurement of boride andthe method for measuring each component in the fluoride brazing flux can also be applied to the measurement of the same component in other brazing fluxes.
Description
Technical Field
The invention relates to a method for measuring effective chemical components in a brazing flux, which is mainly suitable for the brazing flux containing boride and fluoride, and the effective chemical component Na+、B3+、Ca2+、F-The determination of content and water content belongs to the field of component analysis technology.
Background
Welding is a traditional processing means in the manufacturing industry, welding technologies are needed in various industries of national economy, the welding technologies have penetrated into various fields of the manufacturing industry, the metal processing technology formed by welding and other methods such as metal cutting processing, pressure processing, casting, heat treatment and the like becomes a basic production means of various departments of the industries such as automobiles, ships, airplanes, aerospace, atomic energy, petroleum, chemical engineering, electronics and the like, and directly influences the quality, reliability stability, service life, production cost, efficiency and market reaction speed of products. The development level of the welding technology of a country is an important mark of the modernization development level of the industrial and scientific technology, and the welding plays an irreplaceable important role in the construction of national economy and the social development. The brazing flux is a product used for matching welding, and the quality of the brazing flux has a crucial influence on the welding quality.
Along with the needs of national defense and military science and technology, the electronic complete machine develops towards the direction of multifunction and miniaturization, the requirements on electronic accessories are continuously improved, higher and higher requirements are provided for the product quality, and the higher and higher requirements are provided for welding.
In the field of brazing flux detection, the existing detection standards mainly adopt methods such as a gravimetric method, a boiling point method, a potentiometric titration method, a visual titration method, a copper mirror test, a brazing flux efficacy test, the solubility of brazing flux residues, a copper pipe corrosion test, the measurement of brazing flux splashing property and the like, and the detection methods have the defects that (1) the measured result can only indirectly detect whether the brazing flux meets the use requirement, and cannot intuitively and accurately determine whether the brazing flux meets the use requirement; (2) the detection method is greatly interfered by human factors, the relative error is large, and the obtained data are generally relative values and are not as reliable as absolute values. The defects of the two aspects have adverse effects on the detection of products, particularly products related to national defense and military industry, have very high standards and requirements on reliability and stability, and have certain requirements on the reliability and stability as an auxiliary brazing flux which is important for welding, but the existing standards do not have a method for directly and accurately detecting whether the brazing flux meets the requirements, so the method is quite unsuitable and does not accord with the actual requirements of the national defense and military industry, and therefore, a new brazing flux detection method is necessary and urgent to be established as soon as possible.
Disclosure of Invention
The invention aims to provide a method for measuring Na in a brazing flux containing boride and fluoride+、B3+、Ca2+、F--The method for content and water content has the advantages of reducing operation steps to the maximum extent, shortening the determination time, reducing the interference of other elements on the sample, improving the accuracy of the determination result and facilitating the operation. By measuring Na in boride and fluoride mixed brazing flux for high temperature+、B3 +、Ca2+、F-The content and the water content can visually and accurately determine the content of the effective components in the brazing flux.
The method of the invention takes three parallel samples. Loading a sample into a beaker, adding water, heating to dissolve the sample, separating insoluble substances, and measuring Na+、B3+Content (c); another sample is placed in a beaker and hydrochloric acid is added to dissolve the sample and measure Ca2+、F-Content (c); and putting another sample into the crucible and placing the crucible in a muffle furnace, then heating for dehydration, finally cooling along with the furnace and weighing, and measuring the water content of the sample.
A method for measuring the active chemical components in soldering flux is suitable for high-temp use of Na in mixed soldering flux containing boride and fluoride+、B3+、Ca2+、F-The method for measuring the content and the water content comprises the following steps:
(1) weighing the flux sample inAdding water, heating in water bath, filtering while hot, washing with water until the filtrate is neutral, and cooling the filtrate to room temperature; adding a hydrochloric acid standard solution, adding water to a constant volume, and shaking up; removing part of the sample solution, adding bromocresol green-methyl red indicator, titrating to green with sodium hydroxide standard solution, simultaneously performing blank test (using deionized water as reference sample), and calculating Na+Content (c); adding glycerol or mannitol, shaking for dissolving, adding phenolphthalein indicator, titrating with sodium hydroxide standard solution to rose color, simultaneously performing blank test (using deionized water as reference sample), and calculating B3+Content (c);
(2) weighing a brazing flux sample, adding a hydrochloric acid solution into the sample, heating to slightly boil, cooling the test solution to room temperature, adding water to a constant volume, and shaking up; transferring part of the test solution, adding water, triethanolamine solution and sodium hydroxide solution, adding calcium indicator, titrating with EDTA standard solution to pure blue, and calculating Ca2+And F-The content of (A);
(3) weighing a brazing flux sample, putting the brazing flux sample into a muffle furnace for heating and drying, then putting the brazing flux sample into a dryer for cooling to room temperature, weighing, and calculating the water content of the brazing flux sample.
In the step (1), the water bath heating temperature is 80-95 ℃, and the heating time is 35-50 minutes (one range can be given, such as 30-50 minutes); filtering at 40 deg.C or higher, and washing the filtrate with water at 40 deg.C or higher until the filtrate is neutral and pH is 6.5-7.2. Weighing 10g of sample, and accurately weighing the sample to 0.0001 g; the volume of the test solution is removed to 1/20 of the total test solution volume; the glycerol or mannitol is added in an amount of 10-35ml (a range may be given, such as 15-30 ml). The adding amount of the bromocresol green-methyl red indicator and the phenolphthalein indicator is 0.4mL (6 drops), the concentration of the hydrochloric acid standard solution is 1mol/L, the concentration of the sodium hydroxide standard solution adopted in the first measurement is 0.025mol/L, and the concentration of the sodium hydroxide standard solution adopted in the second measurement is 0.25 mol/L.
In step (1), Na+The mass fraction of the content is as omegaNa+In this case, the numerical values are represented by "%" and calculated by the formula (1):
in the formula:
v: the volume of hydrochloric acid standard solution added in milliliters (mL);
V1: the volume of the sodium hydroxide standard solution consumed by the first titration is milliliter (mL);
V0: the volume of sodium hydroxide standard solution consumed for the first titration blank in milliliters (mL);
c: the concentration of the hydrochloric acid standard solution is expressed in units of mol per liter (mol/L);
C1: the concentrations of the first titration test solution and the sodium hydroxide standard solution of the blank test are expressed in mol per liter (mol/L);
Vz: the total volume of the test solution after constant volume is milliliter (mL);
Vy: the volume of the removed portion of the sample solution is in milliliters (mL);
m: sample mass in grams (g);
23: sodium molar mass in grams per mole (g/mol).
In step (1), B3+The mass fraction of the content is as omegaB3+In this case, the numerical values are represented by "%" and calculated by the formula (2):
in the formula:
V2: the volume of the sodium hydroxide standard solution consumed by the second titration is milliliter (mL);
V0': the volume of sodium hydroxide standard solution consumed for the second titration blank in milliliters (mL);
C2: the concentration of the sodium hydroxide standard solution of the second titration test solution and the blank test is in mol per liter (mol/L);
Vz: the total volume of the test solution after constant volume is milliliter (ml)mL)；
Vy: the volume of the removed portion of the sample solution is in milliliters (mL);
m: sample mass in grams (g);
10.81: boron molar mass in grams per mole (g/mol).
In the step (2), weighing 10g of sample, and accurately weighing the sample to 0.0001 g; the volume of the test solution is removed to 1/10 of the total test solution volume; the concentration of the hydrochloric acid solution is 1mol/L, the addition amount is 250-400mL, and the solution is slightly boiled for 25-50min by heating; the adding amount of water is 100mL, the amount of triethanolamine solution is 5mL, the concentration of sodium hydroxide solution is 200g/L, and the adding amount is 20-40 mL; the addition amount of the calcium indicator is 0.4mL, and the concentration of the EDTA standard solution is 0.05 mol/L.
In step (2), Ca2+The mass fraction of the content is as omegaCa2+In this case, the numerical values are represented by "%" and calculated according to formula (3):
in the formula:
C3: the concentration of EDTA standard solution, in units of moles per liter (mol/L);
V3: EDTA standard titrates the volume consumed of the calcium solution in milliliters (mL);
Vz: the total volume of the test solution after constant volume is milliliter (mL);
Vy: the volume of the removed portion of the sample solution is in milliliters (mL);
40.08: calcium molar mass in grams per mole (g/mol);
m: sample mass in grams (g).
In step (2), F-The mass fraction of the content is as omegaF-In this case, the numerical values are represented by "%" and calculated by the formula (4):
in the formula:
19: fluorine molar mass in grams per mole (g/mol);
40.08: calcium molar mass, in grams per mole (g/mol).
In the step (3), when the sample is weighed, the mass is accurate to 0.0001 g; the temperature for heating and drying the brazing flux sample is 300-600 ℃, and the constant temperature time is 1-3 h.
In the step (3), the mass fraction of the water content of the flux sample, the numerical value of which is expressed in "%", is calculated according to the formula (5):
in the formula:
m1: the mass of the brazing flux sample before drying is in gram (g);
m2: the mass of the dried flux sample is given in grams (g).
Compared with the prior art, the invention has the advantages that: (1) the method of the invention determines the effective components in the brazing flux, the determination result is visual and accurate, whether the brazing flux can meet the use requirement can be directly determined through detection, the quality objection can be reduced, and the reliability and stability of the brazing flux product can be ensured; (2) the detection method is fixed, the detection result is visual and accurate, the number is readable and reproducible, and the influence of human factors is reduced to the maximum extent. The method can better protect the driving and navigation of national defense military products, greatly help to improve the reliability and stability of the soldering flux product, provide reference standards for future soldering flux detection development, promote the development of soldering flux related technologies, and ensure the consistency, stability and reliability of the soldering flux product, thereby further ensuring the reliability and stability of the national defense military products served in the fields of aerospace, electronics and the like.
The method for measuring the effective chemical components in the brazing flux is suitable for the brazing flux containing boride and fluoride, and comprises FB105 brazing flux and Pi B200#The content of each component in the brazing flux can be measured, and the method can also be applied to other brazing fluxesDetermination of the same components in the formulation.
Detailed Description
The invention relates to a method for measuring effective chemical components in a brazing flux, which comprises the following steps:
(1) a10.0000 g sample was weighed to the nearest 0.0001g and placed in a 300mL beaker and covered with a watch glass. Adding 200mL of water into a beaker, placing the beaker into a hot water bath at 90 ℃ for heating for 40 minutes, filtering the beaker at the temperature of more than 40 ℃, washing the filtrate with water at the temperature of more than 40 ℃ to be neutral, and cooling the filtrate to room temperature. And adding about 20mL of 1mol/L hydrochloric acid solution, recording the volume of the added hydrochloric acid solution, adding water to a constant volume of 500mL, and shaking up. Transferring 25mL of the test solution, placing the test solution in a 250mL conical flask, adding 0.4mL (6 drops) of bromocresol green-methyl red indicator, titrating the indicator to green by using 0.025mol/L sodium hydroxide standard solution, and recording the volume V of the consumed sodium hydroxide standard solution1、V0(ii) a Then adding 20mL of glycerol, shaking for dissolving, adding 0.4mL (6 drops) of phenolphthalein indicator, titrating to rose color by using 0.25mol/L sodium hydroxide standard solution, and recording the volume V of the sodium hydroxide standard solution consumed2、V0’。
Putting into a hot water bath, filtering, and washing the filtrate until the filtrate is neutral: placing into a hot water bath with constant temperature of 90 deg.C for 40 min, filtering at above 40 deg.C, and washing the filtrate with water at above 40 deg.C to neutrality. The additional reagent can also be added with 20ml mannitol.
Na+The mass fraction of the content is as omegaNa+In this case, the numerical values are represented by "%" and calculated by the formula (1):
in the formula:
v-volume of hydrochloric acid standard solution added in milliliters (mL);
V1-the volume of sodium hydroxide standard solution consumed by the first titration of the test solution in milliliters (mL);
V0the volume of sodium hydroxide standard solution consumed for the first titration of the blank in milliliters (mL);
c-concentration of hydrochloric acid standard solution, wherein the unit is mol per liter (mol/L);
C1the concentrations of the first titration test solution and the blank test sodium hydroxide standard solution in moles per liter (mol/L);
500-total volume of test solution in milliliters (mL);
25-volume of sample removed in milliliters (mL);
m-sample mass in grams (g);
23-sodium molar mass in grams per mole (g/mol).
B3+The mass fraction of the content is as omegaB3+In this case, the numerical values are represented by "%" and calculated by the formula (2):
in the formula:
V2the volume of sodium hydroxide standard solution consumed by the second titration of the test solution in milliliters (mL);
V0' -the volume of sodium hydroxide standard solution consumed for the second titration blank in milliliters (mL);
C2the concentration of the second titration test solution and the sodium hydroxide standard solution of the blank test in moles per liter (mol/L);
500-total volume of test solution in milliliters (mL);
25-volume of sample removed in milliliters (mL);
m-sample mass in grams (g);
10.81-boron molar mass in grams per mole (g/mol).
(2) A10.0000 g sample was weighed to the nearest 0.0001g and placed in a 500ml beaker and covered with a watch glass. Adding 350mL of 1mol/L hydrochloric acid solution into a beaker, covering a watch glass, heating and slightly boiling for 30min, cooling the test solution to room temperature, adding water to a constant volume of 500mL, and shaking up. Transferring 50mL of the sample solution, placing in a 250mL conical flask, adding 100mL of water and 5mL triethanolamine solution, 35mL of 200g/L sodium hydroxide solution, a little calcium indicator, and titrating to pure blue with 0.05mol/L EDTA standard solution. Recording the consumption of EDTA Standard solution volume V3。
Ca2+The mass fraction of the content is as omegaCa2+In this case, the numerical values are represented by "%" and calculated according to formula (3):
in the formula:
C3-concentration of EDTA standard solution in moles per liter (mol/L);
V3-volume consumed in milliliters (mL) by titration of calcium solution with EDTA standard solution;
500-total volume of test solution in milliliters (mL);
50-volume of sample removed in milliliters (mL);
40.08-calcium molar mass in grams per mole (g/mol);
m-sample mass in grams (g).
F-The mass fraction of the content is as omegaF-In this case, the numerical values are represented by "%" and calculated by the formula (4):
in the formula:
19-molar mass of fluorine in grams per mole (g/mol);
40.08-calcium molar mass in grams per mole (g/mol).
(3) 5.0000g of flux is weighed to the nearest 0.0001g, and is recorded as m1. Putting the crucible filled with the soldering flux into a muffle furnace at 350 ℃, keeping the temperature for 1.5h, taking out, putting into a dryer, cooling to room temperature, weighing, and recording as m2。
The mass fraction of the water content of the flux, the numerical value being in "%", is calculated according to formula (5):
in the formula:
m1-mass of flux before drying in grams (g);
m2-mass of flux after drying in grams (g).
The present invention will be further described below by taking FB105 flux as an example.
The FB105 soldering flux is a mixed soldering flux of boride and fluoride for high temperature, and comprises borax, boric acid or boric anhydride and calcium fluoride. In FB105 flux, H3BO3The mass fraction of (A) is 80%; na (Na)2B4O7Is 14.5 percent, CaF2The mass fraction of (a) is 5.5%. According to theoretical calculation, Na+The mass fraction of the content is 3.31 percent; b is3+The mass fraction of the content is 17.11%; ca2+The mass fraction of the content is 2.82 percent; f-The mass fraction of the content is 2.67%; the mass fraction of the water content of the brazing flux is 23.30%.
Example 1
This example shows that in FB105 flux sample I, the effective chemical component Na+、B3+、Ca2+、F-The content and the water content are measured by the following steps:
1. determination of Na and B elements in brazing flux sample
1) Analysis of samples
A10.0000 g sample was weighed to the nearest 0.0001g and placed in a 300mL beaker and covered with a watch glass. Adding 200mL of water into a beaker, placing the beaker into a hot water bath at 90 ℃ for heating for 40 minutes, filtering the beaker at the temperature of more than 40 ℃, washing the filtrate with water at the temperature of more than 40 ℃ to be neutral, and cooling the filtrate to room temperature. And adding about 20mL of 1mol/L hydrochloric acid solution, recording the volume of the added hydrochloric acid solution, adding water to a constant volume of 500mL, and shaking up. Transferring 25mL of the sample solution, placing the sample solution in a 250mL conical flask, adding 0.4mL (6 drops) of bromocresol green-methyl red indicator, titrating the indicator to green by using 0.025mol/L sodium hydroxide standard solution, and recording the consumption of the sodium hydroxideVolume V of sodium standard solution1、V0(ii) a Then adding 20mL of glycerol, shaking for dissolving, adding 0.4mL (6 drops) of phenolphthalein indicator, titrating to rose color by using 0.25mol/L sodium hydroxide standard solution, and recording the volume V of the sodium hydroxide standard solution consumed2、V0’。
2) Calculation of analysis results
Na+The mass fraction of the content is as omegaNa+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
B3+the mass fraction of the content is as omegaB3+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
the calculation result is as follows:
2. determination of Ca and F elements in brazing flux
1) Analysis of samples
A10.0000 g sample was weighed to the nearest 0.0001g and placed in a 500ml beaker and covered with a watch glass. Adding 350mL of 1mol/L hydrochloric acid solution into a beaker, covering a watch glass, heating and slightly boiling for 30min, cooling the test solution to room temperature, adding water to a constant volume of 500mL, and shaking up. 50mL of the sample solution was removed and placed in a 250mL conical flaskIn a bottle, 100mL of water is added, 5mL of triethanolamine solution is added, 35mL of 200g/L sodium hydroxide solution is added, a little calcium indicator is added, and the solution is titrated to pure blue by 0.05mol/L of EDTA standard solution. Recording the consumption of EDTA Standard solution volume V3。
| Sample quality (M) | 10.0000g |
| Concentration of EDTA Standard solution (C)3) | 0.05mol/L |
| EDTA Standard solution titration calcium solution consumption volume (V)3) | 13.93ml |
2) Calculation of analysis results
Ca2+The mass fraction of the content is as omegaCa2+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
F-the mass fraction of the content is as omegaF-In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
the calculation result is as follows:
3. determination of flux water content
1) Analysis of samples
5.0000g of flux is weighed to the nearest 0.0001g, and is recorded as m1. Putting the crucible filled with the soldering flux into a muffle furnace at 350 ℃, keeping the temperature for 1.5h, taking out, putting into a dryer, cooling to room temperature, weighing, and recording as m2。
| Sample mass (m)1) | 5.0001g |
| Mass (m) of dried sample2) | 3.8358g |
2) Calculation of analysis results
The mass fraction of the water content of the flux, the numerical value of which is expressed in "%", is calculated according to the following formula:
the calculation result is as follows:
ω＝23.284％。
example 2
In this example, the effective chemical component Na in the FB105 flux sample II is measured+、B3+、Ca2+、F-The content and the water content are measured by the following steps:
1. determination of Na and B elements in soldering flux
1) Analysis of samples
10.0000g of a sample was weighed,to an accuracy of 0.0001g, place in a 300mL beaker and cover the petri dish. Adding 200mL of water into a beaker, placing the beaker into a hot water bath at 90 ℃ for heating for 40 minutes, filtering the beaker at the temperature of more than 40 ℃, washing the filtrate with water at the temperature of more than 40 ℃ to be neutral, and cooling the filtrate to room temperature. And adding about 20mL of 1mol/L hydrochloric acid solution, recording the volume of the added hydrochloric acid solution, adding water to a constant volume of 500mL, and shaking up. Transferring 25mL of the test solution, placing the test solution in a 250mL conical flask, adding 0.4mL (6 drops) of bromocresol green-methyl red indicator, titrating the indicator to green by using 0.025mol/L sodium hydroxide standard solution, and recording the volume V of the consumed sodium hydroxide standard solution1、V0(ii) a Then adding 20mL of glycerol, shaking for dissolving, adding 0.4mL (6 drops) of phenolphthalein indicator, titrating to rose color by using 0.25mol/L sodium hydroxide standard solution, and recording the volume V of the sodium hydroxide standard solution consumed2、V0’。
| Sample quality (M) | 10.0003g |
| Adding hydrochloric acid solution volume (V) | 20.00ml |
| Adding hydrochloric acid solution with concentration (C) | 1.002mol/L |
| Volume of sodium hydroxide solution consumed for the first titration of the test solution (V)1) | 12.05ml |
| Standard volume of sodium hydroxide consumed for the first titration blank (V)0) | 0.50ml |
| First of allConcentration of sodium hydroxide solution for the Subtraction test solution and blank test (C)1) | 0.02456mol/L |
| Volume of sodium hydroxide solution consumed by the second titration of the test solution (V)2) | 29.63ml |
| Standard volume of sodium hydroxide consumed for the second titration blank (V)0’) | 0.35ml |
| Concentration of sodium hydroxide solution for second titration test solution and blank test (C)2) | 0.2700mol/L |
2) Calculation of analysis results
Na+The mass fraction of the content is as omegaNa+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
B3+the mass fraction of the content is as omegaB3+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
the calculation result is as follows:
4. determination of Ca and F elements in brazing flux
1) Analysis of samples
A10.0000 g sample was weighed to the nearest 0.0001g and placed in a 500ml beaker and covered with a watch glass. Adding 350mL of 1mol/L hydrochloric acid solution into a beaker, covering a watch glass, heating and slightly boiling for 30min, cooling the test solution to room temperature, adding water to a constant volume of 500mL, and shaking up. 50mL of the sample solution was transferred and placed in a 250mL conical flask, 100mL of water was added, 5mL of triethanolamine solution was added, 35mL of 200g/L sodium hydroxide solution was added, a small amount of calcium indicator was added, and the mixture was titrated to pure blue with 0.05mol/L of EDTA standard solution. Recording the consumption of EDTA Standard solution volume V3。
| Sample quality (M) | 9.9999g |
| Concentration of EDTA Standard solution (C)3) | 0.05mol/L |
| EDTA Standard solution titration calcium solution consumption volume (V)3) | 14.14ml |
3) Calculation of analysis results
Ca2+The mass fraction of the content is as omegaCa2+In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
F-the mass fraction of the content is as omegaF-In the following description, the numerical values are expressed in "%" and calculated according to the following formula:
the calculation result is as follows:
5. determination of flux water content
1) Analysis of samples
5.0000g of flux is weighed to the nearest 0.0001g, and is recorded as m1. Putting the crucible filled with the soldering flux into a muffle furnace at 350 ℃, keeping the temperature for 1.5h, taking out, putting into a dryer, cooling to room temperature, weighing, and recording as m2。
| Sample mass (m)1) | 5.0000g |
| Mass (m) of dried sample2) | 3.8320g |
2) Calculation of analysis results
The mass fraction of the water content of the flux, the numerical value of which is expressed in "%", is calculated according to the following formula:
the calculation result is as follows:
ω＝23.36％。
the method is suitable for various brazing fluxes containing boride and fluoride, and the effective chemical component Na+、B3+、Ca2+、F-And (4) measuring the content and the water content. The method of the invention determines the effective components in the brazing flux, the determination result is visual and accurate, whether the brazing flux can meet the use requirement can be directly determined through detection, and the reliability and stability of the product can be better ensured.
Claims (10)
1. A method for measuring effective chemical components in a brazing flux comprises the following steps:
(1) weighing a brazing flux sample, adding water into the sample, heating in a water bath, filtering and washing the filtrate while the sample is hot until the washing liquid is neutral, and cooling the filtrate to room temperature; adding a hydrochloric acid standard solution, adding water to a constant volume, and shaking up; transferring part of the sample solution, adding bromocresol green-methyl red indicator, titrating to green with sodium hydroxide standard solution, simultaneously performing blank test, and calculating Na+Content (c); adding glycerol or mannitol, shaking for dissolving, adding phenolphthalein indicator, titrating with sodium hydroxide standard solution to rose color, performing blank test, and calculating B3+Content (c);
(2) weighing a brazing flux sample, adding a hydrochloric acid solution into the sample, heating to slightly boil, cooling the test solution to room temperature, adding water to a constant volume, and shaking up; transferring part of the test solution, adding water, triethanolamine solution and sodium hydroxide solution, adding calcium indicator, titrating with EDTA standard solution to pure blue, and calculating Ca2+And F-The content of (A);
(3) weighing a brazing flux sample, putting the brazing flux sample into a muffle furnace for heating and drying, then putting the brazing flux sample into a dryer for cooling to room temperature, weighing, and calculating the water content of the brazing flux sample.
2. The method for measuring an active chemical component in a flux according to claim 1, wherein: the temperature of the water bath heating is 80-95 ℃, and the heating time is 35-50 minutes.
3. The method for measuring an active chemical component in a flux according to claim 2, wherein: (ii) a Filtering at 40 deg.C or higher, and washing the filtrate with water at 40 deg.C or higher until the pH of the filtrate is 6.5-7.2.
4. The method for measuring an active chemical component in a flux according to claim 3, wherein: weighing 10g of sample, and accurately weighing the sample to 0.0001 g; the volume of the test solution is removed to 1/20 of the total test solution volume; the addition amount of glycerol or mannitol is 10-35 ml.
5. The method for measuring an active chemical component in a flux according to claim 4, wherein: the adding amount of the bromocresol green-methyl red indicator and the phenolphthalein indicator is 0.4 mL; the concentration of the hydrochloric acid standard solution is 1mol/L, the concentration of the sodium hydroxide standard solution used in the first measurement is 0.025mol/L, and the concentration of the sodium hydroxide standard solution used in the second measurement is 0.25 mol/L.
6. The method for measuring an active chemical component in a flux according to claim 5, wherein: na (Na)+The mass fraction of the content is as omegaNa+In this case, the numerical value is represented by "%" and is calculated by the following formula:
in the formula:
v: the volume of the hydrochloric acid standard solution added is milliliter;
V1: the volume of the sodium hydroxide standard solution consumed by the first titration test solution is milliliter;
V0: the volume of the sodium hydroxide standard solution consumed in the blank test is titrated for the first time, and the unit is milliliter;
c: the concentration of the hydrochloric acid standard solution is expressed in mol per liter;
C1: the concentration of the first titration test solution and the sodium hydroxide standard solution of the blank test is in mol per liter;
Vz: the total volume of the test solution after constant volume is milliliter;
Vy: the volume of the removed part of the test solution is milliliter;
m: sample mass in grams;
23: sodium molar mass in grams per mole;
B3+the mass fraction of the content is as omegaB3+In this case, the numerical value is represented by "%" and is calculated by the following formula:
in the formula:
V2: the volume of the sodium hydroxide standard solution consumed by the second titration test solution is milliliter;
V0': titrating the volume of the sodium hydroxide standard solution consumed in the blank test for the second time, wherein the unit is milliliter;
C2: the concentration of the second titration test solution and the sodium hydroxide standard solution of the blank test is in mol per liter;
Vz: the total volume of the test solution after constant volume is milliliter;
Vy: the volume of the removed part of the test solution is milliliter;
m: sample mass in grams;
10.81: boron molar mass in grams per mole.
7. The method for measuring an active chemical component in a flux according to claim 1, wherein: in the step (2), weighing 10g of sample, and accurately weighing the sample to 0.0001 g; the volume of the test solution is removed to 1/10 of the total test solution volume; the concentration of the hydrochloric acid solution is 1mol/L, the addition amount is 250-400mL, and the solution is slightly boiled for 25-50min by heating; the adding amount of water is 100mL, the amount of triethanolamine solution is 5mL, the concentration of sodium hydroxide solution is 200g/L, and the adding amount is 20-40 mL; the addition amount of the calcium indicator is 0.4mL, and the concentration of the EDTA standard solution is 0.05 mol/L.
8. In the flux of claim 7A method for measuring an active chemical ingredient, characterized by comprising: ca2+The mass fraction of the content is as omegaCa2+In this case, the numerical value is represented by "%" and is calculated by the following formula:
in the formula:
C3: the concentration of EDTA standard solution is expressed in mol per liter;
V3: the volume consumed by titrating the calcium solution by the EDTA standard solution is milliliter;
Vz: the total volume of the test solution after constant volume is milliliter;
Vy: the volume of the removed part of the test solution is milliliter;
40.08: calcium molar mass in grams per mole;
m: sample mass in grams;
F-the mass fraction of the content is as omegaF-In this case, the numerical value is represented by "%" and is calculated by the following formula:
in the formula:
19: molar mass of fluorine, in grams per mole;
40.08: calcium molar mass in grams per mole.
9. The method for measuring an active chemical component in a flux according to claim 1, wherein: in the step (3), when the sample is weighed, the mass is accurate to 0.0001 g; the temperature for heating and drying the brazing flux sample is 300-600 ℃, and the constant temperature time is 1-3 h.
10. The method for measuring an active chemical component in a flux according to claim 9, wherein: the mass fraction of the water content of the flux sample is represented by "%", and the mass fraction is calculated according to the following formula:
in the formula:
m1: the mass of the brazing flux sample before drying is in grams;
m2: the mass of the dried brazing flux sample is gram.
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