Method for detecting purification treatment effect of aluminum and aluminum alloy

Abstract

An aluminum and aluminum alloy purification treatment effect detection method belongs to the field of aluminum and aluminum alloy purification treatment, and comprises the following steps: S1, melting aluminum or aluminum alloy to obtain a melt; s2, sampling is conducted in n different areas in the melt, n first detection samples are obtained, and n is larger than or equal to 3; carrying out B element content detection on the first detection sample through a direct-reading spectrometer, and calculating an average value C1 of the B element content; s3, the melt is subjected to purification treatment; s4, respectively sampling in the same sampling area as the step S2, totally obtaining n second detection samples, and detecting and calculating an average value C2 of the content of the B element; and S5, the B element removal rate eta is calculated according to the formula eta = (C1-C2) / C1 * 100%, and the purity of the melt is judged according to the B element removal rate eta. According to the method, the removal efficiency of the element B is calculated by detecting the change of the content of the element B in the aluminum and aluminum alloy melt before and after purification treatment, so that the removal effect of the TiB2 particles is indirectly judged, and finally, the accurate detection of the overall purification treatment effect of the aluminum and aluminum alloy melt is realized.

Description

Technical Field

[0001] This invention relates to the field of purification treatment of aluminum and aluminum alloys, specifically a method for detecting the purification effect of aluminum and aluminum alloys. Background Technology

[0002] In the aluminum and aluminum alloy production industry, accurate and efficient testing of melt purification effects is a crucial step in ensuring product quality. Currently, the mainstream methods for testing purification effects in the industry mainly include vacuum solidification, online hydrogen measurement, and metallographic slag analysis. However, these methods generally have significant limitations and cannot meet the demands of high-quality production. Specifically, vacuum solidification and online hydrogen measurement are affected by the testing principles and environmental factors, resulting in large errors in the test results and failing to accurately reflect the true removal of inclusions in the melt. Metallographic slag analysis requires sampling and testing after product molding, which has a serious time lag. If purification is found to be substandard, the molded product faces the risk of being scrapped, resulting in resource waste, significantly increased production costs, and extremely poor timeliness. Furthermore, in the aluminum industry, except for conductive aluminum, almost all aluminum and aluminum alloy products require the introduction of titanium (Ti) and boron (B) elements during the production process. These elements react to generate heterogeneous nucleated titanium diboride (TiB2) particles, thereby refining the grains and improving the material's mechanical properties. It is particularly noteworthy that TiB2 particles possess unique physical characteristics: their diameter is typically less than 2 micrometers, significantly smaller than alumina inclusions which are generally larger than 5 micrometers. Moreover, TiB2 particles exhibit a higher degree of dispersion in molten aluminum. In the process of removing alumina inclusions using conventional processes such as inert gas refining or flux purification, solid TiB2 particles can theoretically be removed along with the inclusions. However, due to the smaller size and greater dispersion of TiB2 particles, their actual removal difficulty is far greater than that of alumina inclusions. But this high difficulty in removal makes them a more accurate indicator of the overall purification effect of the melt. Summary of the Invention

[0003] This invention provides a method for detecting the purification effect of aluminum and aluminum alloys. By detecting the change in the content of element B in the aluminum and aluminum alloy melt before and after purification treatment, the removal efficiency of element B is calculated, thereby indirectly determining the removal effect of TiB2 particles, and finally achieving accurate detection of the overall purification effect of aluminum and aluminum alloy melt.

[0004] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a method for detecting the purification effect of aluminum and aluminum alloys, comprising the following steps: S1. Melt and stir aluminum or aluminum alloy to obtain a melt; S2. Take samples from n different regions in the melt to obtain n first test samples, where n≥3; use a direct-reading spectrometer to detect the B element content of the first test samples, and calculate the average B element content of the n first test samples, which is denoted as the average B element content before purification C1. S3. Purify the melt; S4. After the purification process is completed, samples are taken from the same sampling area as in step S2, and a total of n second test samples are obtained. The B element content of the n second test samples is detected by a direct reading spectrometer, and the average B element content of the n second test samples is calculated and recorded as the average B element content C2 after purification. S5. Calculate the B element removal rate η according to the formula η=(C1-C2) / C1×100%, and determine the purity of the melt by the B element removal rate η.

[0005] As a further optimization of the above technical solution, the specific standard for determining the purity of the melt by the B element removal rate η in step S5 is as follows: When η < 3%, the purity of the melt is determined to be lower than Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 3%≤η<10%, the purity of the melt is determined to reach Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 10%≤η<30%, the purity of the melt is determined to reach Grade II in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 30%≤η<50%, the purity of the melt is determined to reach Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When η≥50%, the purity of the melt is determined to be higher than Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". As a further optimization of the above technical solution, the feature is that the three sampling areas are located near the center of the molten pool and the two corner areas at the furnace entrance.

[0006] As a further optimization of the above technical solution, the weight of the first and second test samples is 50-150g.

[0007] As a further optimization of the above technical solution, the purification process in step S3 involves injecting powdered or granular refining agent into the melt using inert gas.

[0008] As a further optimization of the above technical solution, the inert gas is high-purity nitrogen or argon.

[0009] As a further optimization of the above technical solution, the refining agent includes chloride salts and fluoride salts, wherein the chloride salts account for 60%-90% of the mass of the refining agent, and the remaining component is fluoride salts.

[0010] As a further optimization of the above technical solution, the chloride salt is at least one of sodium chloride, potassium chloride, and magnesium chloride, and the fluoride salt is at least one of calcium fluoride, potassium fluoride, and potassium fluoroaluminate.

[0011] As a further optimization of the above technical solution, the melt in step S1 is a melt containing titanium and boron elements.

[0012] As a further optimization of the above technical solution, in step S1, an inert gas or an electromagnetic stirrer is used to stir the molten aluminum or aluminum alloy to obtain the corresponding melt.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention rapidly and accurately determines the purity of aluminum and aluminum alloy melts by detecting the removal efficiency of element B before and after purification treatment. Casting is then carried out only after the purity meets the requirements, thus ensuring product quality.

[0014] This invention, based on the stoichiometric relationship between TiB2 content and boron (B) content, uses the B removal efficiency as a criterion for determining melt purity. By detecting changes in B content, it indirectly achieves simultaneous quantification of the removal effect of composite inclusions such as TiB2 particles and alumina. This approach avoids the difficulty of directly detecting TiB2 particles due to their small size and high dispersion, while also enabling precise detection of B through direct-reading spectrometry, significantly improving the accuracy of purity testing.

[0015] This invention employs multi-point sampling, which can cover areas with different inclusion distributions within the molten pool, while reducing random errors caused by local microscopic inhomogeneities. Since inclusions tend to accumulate near the furnace entrance, while inclusions are relatively uniform in the furnace center, this invention uses areas near the center of the molten pool and the two corners of the furnace entrance to calculate the average value. On the one hand, this covers both the areas where inclusions tend to accumulate and the areas where inclusions are relatively uniform within the molten pool, ensuring that the sample represents the overall state of the molten pool. On the other hand, the operation of averaging three samples further reduces random errors caused by local microscopic inhomogeneities, making the B element content detection results more statistically significant and providing a more reliable data basis for subsequent purity determination. Detailed Implementation

[0016] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.

[0017] This invention discloses a method for detecting the purification effect of aluminum and aluminum alloys, comprising the following steps: S1. Melt and stir aluminum or aluminum alloy to obtain the corresponding melt. Specifically, stir the molten aluminum or aluminum alloy using an inert gas or an electromagnetic stirrer to obtain the melt. The inert gas is high-purity nitrogen or argon with a purity greater than 99.99%. The melt contains titanium and boron. During the production of aluminum and aluminum alloy products, titanium and boron elements need to be introduced to generate heterogeneous nucleation particles of titanium diboride (TiB2) through their reaction, thereby refining the grains and improving the mechanical properties of the material. The titanium and boron elements are introduced into the melt by being carried in from the recycled materials.

[0018] S2. Take samples from n different regions in the melt to obtain n first test samples, where n≥3; use a direct-reading spectrometer to detect the B element content of the first test samples, and calculate the average B element content of the n first test samples, which is denoted as the average B element content before purification, C1.

[0019] S3. The melt is purified by injecting an inert gas with a powdered or granular refining agent. The refining agent includes chloride and fluoride salts, wherein the chloride salt accounts for 60%-90% of the refining agent by mass, and the remainder is fluoride salt. The chloride salt is at least one of sodium chloride, potassium chloride, and magnesium chloride, and the fluoride salt is at least one of calcium fluoride, potassium fluoride, and potassium fluoroaluminate. The inert gas is high-purity nitrogen or argon with a purity greater than 99.99%. S4. After the purification process is completed, samples are taken from the same sampling area as in step S2, and a total of n second test samples are obtained. The content of element B in the second test samples is detected by a direct-reading spectrometer, and the average content of element B in the n second test samples is calculated and recorded as the average content of element B after purification, C2. S5. Calculate the B element removal efficiency η according to the formula η=(C1-C2) / C1×100%, and determine the purity of the melt by the B element removal efficiency η.

[0020] The specific criteria for determining the purity of a melt by the B element removal efficiency η are as follows: When η < 3%, the purity of the melt is determined to be lower than Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 3%≤η<10%, the purity of the melt is determined to reach Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 10%≤η<30%, the purity of the melt is determined to reach Grade II in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 30%≤η<50%, the purity of the melt is determined to reach Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When η≥50%, the purity of the melt is determined to be higher than Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". Preferably, n=3, with the three sampling areas located near the center of the molten pool and at the two corners of the furnace entrance. Since inclusions tend to accumulate near the furnace entrance, while inclusions are relatively uniform in the center, this invention uses areas near the center of the molten pool and at the two corners of the furnace entrance to calculate the average value. This covers both the inclusion-accumulation area and the relatively uniform inclusion area within the molten pool, ensuring the sample represents the overall state of the molten pool. Furthermore, the three-point sampling and averaging operation further reduces random errors caused by local micro-inhomogeneities, making the B element content detection results more statistically significant and providing a more reliable data basis for subsequent purity determination.

[0021] The weight of the first and second test samples is 50-150g. The specific sampling method is based on existing technology and will not be described in detail here.

[0022] Example 1 This embodiment describes the detection of the purification treatment results of aluminum melt during the production of 6063 grade aluminum rods, including the following steps: S1. Melt aluminum into an aluminum melt, which is an aluminum melt with titanium and boron elements introduced.

[0023] S2. The aluminum melt volume is 25 tons. High-purity nitrogen is used for stirring. After stirring, three first test samples are taken from the center of the molten pool and two corners of the furnace door. The B content of the first test samples is detected by direct reading spectrometer. The average B content of the three first test samples is C1=230ppm.

[0024] S3. High-purity nitrogen gas is used to inject a powdered refining agent into the molten aluminum for purification. The refining agent consists of sodium chloride, potassium chloride, calcium fluoride, and sodium fluoroaluminate, with chloride salts accounting for 85% and fluoride salts accounting for 15%, at a dosage of 25 kg. The purification treatment temperature for the molten aluminum is 730℃, and the treatment time is 20 minutes.

[0025] S4. After processing, use a sampler to take three second test samples from the center of the molten pool and two corners of the furnace door. Use a direct-reading spectrometer to detect the B content of the second test samples. The average B content of the three second test samples is C2=228ppm.

[0026] S5. Calculate the removal efficiency η of element B using η = (C1-C2) / C1×100%, η = (230-228) / 230×100% = 0.87%. The removal efficiency of element B is less than 3%.

[0027] The aluminum molten material was subjected to water-release casting. After casting, a sample of the finished product was taken and subjected to microstructure testing in accordance with the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". Inclusions larger than 100 micrometers were found, and the purity was lower than Grade III.

[0028] Example 2 This embodiment describes the detection of the purification treatment results of aluminum melt during the production of 6063 grade aluminum rods, including the following steps: S1. Melt aluminum into an aluminum melt, which is an aluminum melt with titanium and boron elements introduced.

[0029] S2. The aluminum melt volume is 25 tons. High-purity argon gas is used for stirring. After stirring, a sampler is used to take the first test sample near the center of the molten pool and at two corners of the furnace door. The B content of the first test sample is detected by a direct-reading spectrometer. The average B content of the three first test samples is 180 ppm.

[0030] S3. High-purity argon gas is used to inject a powdered refining agent into the molten aluminum for purification. The refining agent consists of sodium chloride, potassium chloride, calcium fluoride, and potassium fluoroaluminate, with chloride salts accounting for 85% and fluoride salts accounting for 15%, at a dosage of 25 kg. The purification treatment temperature for the molten aluminum is 720℃, and the treatment time is 20 minutes.

[0031] S4. After the purification process is completed, three second test samples are taken from the center of the molten pool and the two corners of the furnace door using a sampler. The B content of the second test samples is detected by a direct-reading spectrometer. The average B content of the three second test samples is 165 ppm.

[0032] S5, η=(C1-C2) / C1×100% calculate the removal efficiency of element B, η, the removal efficiency of element B is 8.3%.

[0033] After casting, samples were taken and subjected to low-magnification and microstructure analysis according to the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". The low-magnification microstructure showed 3 inclusions, while the microstructure showed no inclusions larger than 100 micrometers and the number of inclusions smaller than 100 micrometers was less than 10 per cm. 2 The purity level is Level III.

[0034] Example 3 This embodiment describes the detection of the purification treatment results of aluminum melt during the production of 6063 grade aluminum rods, including the following steps: S1. Melt aluminum into an aluminum melt, which is an aluminum melt with titanium and boron elements introduced.

[0035] S2. The aluminum melt volume is 25 tons. High-purity argon gas is used for stirring. After stirring, three first test samples are taken from the center of the molten pool and two corners of the furnace door. The B content of the first test samples is detected by direct reading spectrometer. The average B content of the three first test samples is 215 ppm.

[0036] S3. Subsequently, a powdered refining agent was injected into the molten aluminum using high-purity argon gas for purification. The refining agent consisted of sodium chloride, potassium chloride, potassium fluoride, and potassium fluoroaluminate, with chloride salts accounting for 80% and fluoride salts accounting for 20%, at a dosage of 50 kg. The purification treatment temperature for the molten aluminum was 725℃, and the treatment time was 40 minutes.

[0037] S4. After the purification process is completed, three second test samples are taken from the center of the molten pool and the two corners of the furnace door using a sampler. The B content of the second test samples is detected by a direct-reading spectrometer. The average B content of the three second test samples is 170 ppm.

[0038] S5, η=(C1-C2) / C1×100% calculate the removal efficiency of element B, η, the removal efficiency of element B is 20.9%.

[0039] After casting, samples were taken and subjected to low-magnification and microstructure analysis according to the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". The low-magnification microstructure showed one inclusion, while the microstructure showed no inclusions larger than 100 micrometers and the number of inclusions smaller than 100 micrometers was less than 10 per cm. 2 The purity level is Grade II.

[0040] Example 4 This embodiment describes the detection of the purification results of aluminum melt during the production of 6061 grade aluminum rods, including the following steps: S1. Melt aluminum into an aluminum melt, which is an aluminum melt with titanium and boron elements introduced.

[0041] S2. The aluminum melt volume is 40 tons. High-purity argon gas is used for stirring. After stirring, three first test samples are taken from the center of the molten pool and two corners of the furnace door using a sampler. The B content of the first test samples is detected by a direct-reading spectrometer. The average B content of the three first test samples is 325 ppm.

[0042] S3. Subsequently, high-purity argon gas is injected into the molten aluminum to purify it. The refining agent consists of magnesium chloride, potassium chloride, calcium fluoride, and potassium fluoroaluminate, with chloride salts accounting for 85% and fluoride salts accounting for 15%, at a dosage of 60 kg. The purification treatment temperature for the molten aluminum is 735℃, and the treatment time is 40 minutes.

[0043] S4. After the purification process is completed, three second test samples are taken from the center of the molten pool and the two corners of the furnace door using a sampler. The B content of the second test samples is detected by a direct-reading spectrometer. The average B content of the three second test samples is 197 ppm.

[0044] S5, η=(C1-C2) / C1×100% calculate the removal efficiency of element B, η, the removal efficiency of element B is 39.3%.

[0045] After casting, samples were taken and subjected to low-magnification and microstructure analysis according to the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". The low-magnification microstructure showed no inclusions, and the microstructure showed no inclusions larger than 50 micrometers and the number of inclusions smaller than 50 micrometers was less than 5 per cm. 2 The purity level is Grade I.

[0046] Example 5 This embodiment describes the detection of the purification results of aluminum melt during the production of 3003 grade aluminum ingots, including the following steps: S1. Melt aluminum into an aluminum melt, which is an aluminum melt with titanium and boron elements introduced.

[0047] S2. The aluminum melt volume is 80 tons. High-purity argon gas is used for stirring. After stirring, three first test samples are taken from the center of the molten pool and two corners of the furnace door. The B content of the first test samples is detected by direct reading spectrometer. The average B content of the three first test samples is 120 ppm.

[0048] S3. High-purity argon gas is used to inject granular refining agent into the aluminum melt for purification. The refining agent consists of magnesium chloride, potassium chloride, potassium fluoride, and potassium fluoroaluminate, with chloride salts accounting for 70% and fluoride salts accounting for 30%, at a dosage of 160 kg. The aluminum melt purification treatment temperature is 730℃, and the treatment time is 60 minutes.

[0049] S4. After the purification process is completed, three second test samples are taken from the center of the molten pool and the two corners of the furnace door using a sampler. The B content of the three second test samples is detected by a direct-reading spectrometer. The average B content of the three second test samples is 30 ppm.

[0050] S5, η=(C1-C2) / C1×100% calculate the removal efficiency of element B, η, the removal efficiency of element B is 75%.

[0051] Water-casting was carried out, and after casting, a sample of the finished product was taken for low-magnification and microstructure testing in accordance with the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots". The low-magnification structure showed no inclusions, and the microstructure showed that the size of inclusions in the aluminum melt was less than 20 micrometers and the number of inclusions per square centimeter was less than 3, with a purity higher than Grade I.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting the purification effect of aluminum and aluminum alloys, characterized in that, Includes the following steps: S1. Melt and stir aluminum or aluminum alloy to obtain a melt; S2. Take samples from n different regions in the melt to obtain n first test samples, where n≥3; use a direct-reading spectrometer to detect the B element content of the first test samples, and calculate the average B element content of the n first test samples, which is denoted as the average B element content before purification C1. S3. Purify the melt; S4. After the purification process is completed, samples are taken from the same sampling area as in step S2, and a total of n second test samples are obtained. The B element content of the n second test samples is detected by a direct reading spectrometer, and the average B element content of the n second test samples is calculated and recorded as the average B element content C2 after purification. S5. Calculate the B element removal rate η according to the formula η=(C1-C2) / C1×100%, and determine the purity of the melt by the B element removal rate η.

2. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, The specific criteria for determining the purity of the melt in step S5 by the removal rate η of element B are as follows: When η < 3%, the purity of the melt is determined to be lower than Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 3%≤η<10%, the purity of the melt is determined to reach Grade III in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 10%≤η<30%, the purity of the melt is determined to reach Grade II in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When 30%≤η<50%, the purity of the melt is determined to reach Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots"; When η≥50%, the purity of the melt is determined to be higher than Grade I in the national standard GB / T32186 "Test Method for Purity of Aluminum and Aluminum Alloy Ingots".

3. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, The weight of both the first and second test samples is 50-150g.

4. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, n=3, and the three sampling areas are located near the center of the molten pool and the two corner areas at the furnace entrance.

5. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, In step S3, the purification process involves injecting powdered or granular refining agents into the melt using inert gas.

6. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 5, characterized in that, The inert gas is high-purity nitrogen or argon.

7. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 5, characterized in that, Refining agents include chloride salts and fluoride salts, with chloride salts accounting for 60%-90% of the mass of the refining agent, and the remaining component being fluoride salts.

8. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 7, characterized in that, The chloride salt is at least one of sodium chloride, magnesium chloride, and potassium chloride, and the fluoride salt is at least one of calcium fluoride, potassium fluoride, potassium fluoroaluminate, and sodium fluoroaluminate.

9. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, In step S1, the melt is a melt containing titanium and boron elements.

10. The method for detecting the purification effect of aluminum and aluminum alloys according to claim 1, characterized in that, In step S1, inert gas or an electromagnetic stirrer is used to stir the molten aluminum or aluminum alloy to obtain a melt.