A refining method for ZLD cast aluminum alloy
Through the refining method of ZLD cast aluminum alloy, the three-refining treatment and argon gas combination process is adopted to solve the problem of pores and oxide inclusion in the aluminum alloy smelting process, and the purification effect and mechanical properties of the aluminum alloy are significantly improved.
Patent Information
- Application Number
- CN202411914087.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-04-04
AI Technical Summary
During the melting and casting process of aluminum alloy, adsorbed water or crystallized water decomposition forms hydrogen, resulting in the generation of pores, and at the same time, the oxidation reaction forms oxides, resulting in the layering of the castings, corrosion accelerated, and mechanical properties are reduced. The prior art often uses one-time refining, which can easily bring in impurities and affect performance.
The refining method of ZLD cast aluminum alloy is adopted. Through three refining treatments, combined with argon and particulate refining flux, the scum and impurities on the melt surface are gradually removed, and the chemical composition of the aluminum alloy is ensured to meet the needs through component detection and feed adjustment.
Through multiple refining treatments, the purification effect of aluminum alloy is significantly improved, the impurity content is reduced, the crystal nucleus is promoted, and the crystal nucleus is formed is obtained, the small and uniform grain structure is obtained, the product quality is avoided due to local component segregation, and the mechanical properties of the castings are improved.
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Figure CN119753410A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of metallurgy, in particular to a refining method for a ZLD cast aluminum alloy. Background Art
[0002] Aluminum alloys are widely used in aerospace, transportation, machinery, electronics, construction and other fields. They are the most important basic materials for lightweight structures and occupy an important position in the national economy.
[0003] During the smelting and casting process of aluminum and aluminum alloys, the adsorbed water or crystal water that may be contained in the aluminum alloy raw materials decomposes to form hydrogen during smelting and mixes into the melt. During the cooling and solidification of the aluminum liquid, due to the reduction of solubility, it precipitates to form bubbles, resulting in the appearance of pores inside. At the same time, during the smelting process, the aluminum liquid is exposed to the air, and an oxidation reaction occurs on the surface to generate oxides, which cause oxide inclusions to exist in the matrix as non-metallic phases, thereby introducing crack diffusion in the subsequent processing process, causing casting delamination, accelerating the corrosion of the aluminum alloy, and reducing mechanical properties.
[0004] In the existing smelting process, a single refining method is mostly used, which easily introduces impurities and thus affects the performance of the aluminum alloy. Summary of the invention
[0005] Technical problems solved by the present invention:
[0006] To solve the deficiencies in the prior art.
[0007] The technical solution adopted by the present invention is:
[0008] In view of the above-mentioned technical problems, the object of the present invention is to provide a refining method for ZLD cast aluminum alloy.
[0009] Based on this, the specific implementation plan is:
[0010] A refining method for ZLD cast aluminum alloy comprises the following steps:
[0011] (1) feeding materials according to the proportion of ZLD cast aluminum alloy, and putting the raw materials into a smelting furnace for smelting;
[0012] (2) Using argon gas and granular refining flux for the first refining treatment, scraping off the scum on the surface of the melt, and then conducting component testing, and making the first feed according to the chemical composition;
[0013] (3) Continue to use argon gas and granular refining flux for the second refining treatment, scrape off the scum on the surface of the melt, and then perform component detection, and make a second feed according to the chemical composition;
[0014] (4) continuing to use argon gas and granular refining flux for a third refining treatment, scraping off the scum on the surface of the melt, and then letting the cast aluminum alloy melt stand for a period of time to obtain a cast aluminum alloy liquid;
[0015] The total dosage of the tertiary particle refining flux is 1.5-2 kg / t.Al; the components of the particle refining flux, calculated by weight, include 40-60 parts of aluminum fluoride, 1-5 parts of calcium fluoride, 1-3 parts of cerium fluoride, 1-3 parts of lanthanum fluoride, 10-20 parts of sodium chloride, 10-20 parts of potassium chloride, 5-10 parts of sodium carbonate, and 5-10 parts of sodium borate.
[0016] According to some preferred embodiments, during the three refining processes, the volume concentration of argon is ≥ 99.99%; the argon pressure is 0.1-0.2 MPa;
[0017] According to some preferred embodiments, the first refining temperature is ≥780°C, and the refining time is ≥25 min.
[0018] According to some preferred embodiments, the second refining temperature is 740-750° C., and the refining time is ≥20 min.
[0019] According to some preferred embodiments, the third refining temperature is 740-750° C., and the refining time is ≥20 min.
[0020] Through multiple refining treatments, the purification effect can be further improved, thereby ensuring that the impurity content in the final product is low; through multiple refining treatments, the formation of crystal nuclei can be promoted, thereby forming a fine and evenly distributed grain structure, and the product quality can be avoided from being affected by local component segregation.
[0021] According to some preferred embodiments, refining method: double-tube simultaneous refining: using "Z"-type tube and "N"-type tube alternately. Through the double-tube simultaneous refining method, the flow path length and complexity of the aluminum liquid in the pipeline can be increased, thereby increasing the contact time and contact area between the aluminum liquid and the argon gas, so as to further remove hydrogen, oxide inclusions and non-metallic impurities in the aluminum liquid. Alternating the two tubes can make the argon gas dispersed evenly in the aluminum liquid, thereby improving the defect of insufficient local refining. At the same time, it can also help control the speed and direction of the flow of the aluminum liquid, reduce the occurrence of turbulence and eddy current phenomena, and thus reduce the splash loss during the refining process.
[0022] According to some preferred embodiments, the slag removal method is carpet-style slag removal without dead corners, which can avoid material waste caused by residual slag, and can effectively keep the purity of aluminum liquid by completely removing the slag.
[0023] According to some preferred embodiments, the first feed temperature is ≥ 745°C.
[0024] According to some preferred embodiments, the second feed temperature is 745-760°C.
[0025] The chemical composition of aluminum alloy can be adjusted and optimized through the feeding process to meet the use requirements. It can avoid the deviation of the actual melt composition from the predetermined target value due to the loss of elements and the influence of impurities during the smelting process. Through feeding, insufficient alloy elements can be supplemented to ensure the composition accuracy of the final product.
[0026] According to some preferred embodiments, the raw material components of the refining flux are preferably 40-50 parts of aluminum fluoride, 1-3 parts of calcium fluoride, 1-3 parts of cerium fluoride, 1-3 parts of lanthanum fluoride, 10-15 parts of sodium chloride, 10-15 parts of potassium chloride, 5-8 parts of sodium carbonate, and 5-8 parts of sodium borate.
[0027] The preparation method of the refined flux is to weigh the aforementioned raw material components in proportion, dry them at the same time, blend the raw material components, and then bake them at 230-260° C. to obtain the refined flux.
[0028] The technical mechanism and beneficial effects adopted by the present invention are as follows:
[0029] (1) The refining flux provided by the present application can effectively combine with oxygen in the aluminum alloy to form a stable compound, thereby reducing the inclusion of oxides. The combination of chloride and fluoride can significantly reduce the melting point of the flux and provide good fluidity, thereby ensuring that the flux can be evenly distributed on the surface of the melt; at the same time, it can enhance the ability of the flux to capture and release gas, thereby avoiding the occurrence of internal porosity defects to a certain extent.
[0030] (3) The refining process provided by the present invention can effectively avoid the occurrence of quality defects such as slag inclusion, pores, looseness / coarse grains in aluminum alloys through argon gas combined with multiple powder spraying refining processes, thereby improving the comprehensive mechanical properties of large-section aluminum alloy round ingots. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 The actual pictures of the aluminum alloys prepared in Example 2 and Comparative Example 1;
[0032] Figure 2 for Figure 1 Actual picture from another perspective. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.
[0034] Example 1
[0035] Weigh 50 parts of aluminum fluoride, 3 parts of calcium fluoride, 2 parts of cerium fluoride, 2 parts of lanthanum fluoride, 15 parts of sodium chloride, 15 parts of potassium chloride, 8 parts of sodium carbonate, and 8 parts of sodium borate in proportion, weigh them, dry them, blend them, and bake them at 240°C to obtain a refined flux.
[0036] Example 2
[0037] This embodiment provides a refining method for ZLD-102 cast aluminum alloy, comprising the following steps:
[0038] According to the proportion of each raw material of aluminum alloy, all raw materials are put into the melting furnace for melting. The proportion of each element is as follows:
[0039] element Si Mg Ti Fe Cu Zn Mn Al content 12.5 0.05 0.10 0.80 0.2 0.08 0.40 margin
[0040] First refining: the refining temperature is controlled at 780°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.8kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled at 30min, and after the refining is completed, the slag is skimmed, and then the material is supplemented after sampling and testing, and the supplementary material temperature is controlled at 750°C.
[0041] Second refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.6kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled at 25min, and after the refining is completed, the slag is removed, and then the material is supplemented after sampling and testing, and the supplementary material temperature is controlled at 750°C.
[0042] The third refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.6kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled to be 25min, and after the slag is skimmed and degassed, the impurities in the aluminum liquid are filtered out with a honeycomb ceramic filter, and then the aluminum alloy ingot is cast.
[0043] Example 3
[0044] This embodiment provides a refining method for ZLD-104 cast aluminum alloy, comprising the following steps:
[0045] According to the proportion of each raw material of aluminum alloy, all raw materials are put into the melting furnace for melting. The proportion of each element is as follows:
[0046] element Si Mg Ti Fe Cu Zn Mn Al content 8.5 0.25 0.10 0.35 0.08 0.20 0.4 margin
[0047] First refining: the refining temperature was controlled at 780°C, the refining flux obtained in Example 1 was added, wherein the amount of the refining flux was 1.0 kg / t.Al, and argon gas with a concentration of ≥99.99% was introduced at the same time, the argon gas pressure was controlled at 0.1-0.2 MPa, and the refining was carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time was controlled at 25 minutes, and after the refining was completed, the slag was skimmed, and then the material was supplemented after sampling and testing, and the supplementary material temperature was controlled at 750°C.
[0048] Second refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.4kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled at 20min, and after the refining is completed, the slag is skimmed, and then the material is supplemented after sampling and testing, and the supplementary material temperature is controlled at 750°C.
[0049] The third refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.4kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled to be 20min, and after the slag is skimmed and degassed, the impurities in the aluminum liquid are filtered out with a honeycomb ceramic filter, and then the aluminum alloy ingot is cast.
[0050] Example 4
[0051] This embodiment provides a refining method for ZLD-107 cast aluminum alloy, comprising the following steps:
[0052] According to the proportion of each raw material of aluminum alloy, all raw materials are put into the melting furnace for melting. The proportion of each element is as follows:
[0053] element Si Mg Ti Fe Cu Zn Mn Al content 7.0 0.10 0.20 0.45 4.0 0.20 0.4 margin
[0054] First refining: the refining temperature is controlled at 780°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.8kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled at 30min, and after the refining is completed, the slag is skimmed, and then the material is supplemented after sampling and testing, and the supplementary material temperature is controlled at 750°C.
[0055] Second refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.6kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled at 25min, and after the refining is completed, the slag is removed, and then the material is supplemented after sampling and testing, and the supplementary material temperature is controlled at 750°C.
[0056] The third refining: the refining temperature is controlled at 750°C, the refining flux obtained in Example 1 is added, wherein the amount of the refining flux is 0.6kg / t.Al, and argon gas with a concentration of ≥99.99% is introduced at the same time, the argon gas pressure is controlled at 0.1-0.2MPa, and the refining is carried out in an alternating manner of "Z" type tube and "N" type tube. The refining time is controlled to be 25min, and after the slag is skimmed and degassed, the impurities in the aluminum liquid are filtered out with a honeycomb ceramic filter, and then the aluminum alloy ingot is cast.
[0057] Comparative Example 1
[0058] The difference between this comparative example and Example 1 is that only one refining is used and the amount of refining flux used is 2 kg / t.Al.
[0059] Comparative Example 2
[0060] The difference between this comparative example and Example 1 is that the refining flux does not include fluoride.
[0061] Comparative Example 3
[0062] The difference between this comparative example and Example 1 is that the refining flux does not include potassium chloride, sodium carbonate and sodium borate.
[0063] The aluminum alloys prepared in Example 2 and Comparative Example 1 are as follows: Figure 1 to Figure 2 shown.
[0064] Figure 1 The above is Example 2, Figure 1 The following is Comparative Example 1. Figure 2 The above is Example 2, Figure 2 The following is Comparative Example 1.
[0065] The aluminum alloys prepared in Examples 2-4 and Comparative Examples 1-3 were used as samples for measurement. The measurement results are shown in Table 1.
[0066] Table 1 (Example-E, Comparative Example-C)
[0067]
[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A refining method for ZLD cast aluminum alloy, characterized in that: The steps include: (1) feeding materials according to the proportion of ZLD cast aluminum alloy, and putting the raw materials into a smelting furnace for smelting; (2) Using argon gas and granular refining flux for the first refining treatment, scraping off the scum on the surface of the melt, and then performing component testing, and making the first feed according to the chemical composition; (3) Continue to use argon gas and granular refining flux for the second refining treatment, scrape off the scum on the surface of the melt, and then perform component detection, and make a second feed according to the chemical composition; (4) Then, the argon gas and the particle refining flux are used for the third refining treatment to scrape off the scum on the surface of the melt, and then the cast aluminum alloy melt is allowed to stand for a period of time to obtain the cast aluminum alloy liquid.
2. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The total dosage of the tertiary particle refining flux is 1.5-2 kg / t.Al; the components of the particle refining flux, calculated by weight, include 40-60 parts of aluminum fluoride, 1-5 parts of calcium fluoride, 1-3 parts of cerium fluoride, 1-3 parts of lanthanum fluoride, 10-20 parts of sodium chloride, 10-20 parts of potassium chloride, 5-10 parts of sodium carbonate, and 5-10 parts of sodium borate.
3. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The first refining temperature is ≥780℃ and the refining time is ≥25min.
4. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The second refining temperature is 740-750°C and the refining time is ≥20min.
5. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The third refining temperature is 740-750°C and the refining time is ≥20min.
6. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The first feeding temperature is ≥745℃.
7. The refining method of ZLD cast aluminum alloy according to claim 1, characterized in that: The second feeding temperature is 745~760℃.
8. The refining method of ZLD cast aluminum alloy according to any one of claims 1 to 7, characterized in that: Refining method: Double-tube simultaneous refining: using "Z" type tube and "N" type tube alternately.
9. The refining method of ZLD cast aluminum alloy according to claim 8, characterized in that: Slag removal method: Carpet-style slag removal with no dead corners.
10. A casting aluminum alloy liquid obtained by the refining method according to any one of claims 1 to 9, and then subjected to a casting process to obtain an aluminum alloy.