Iron element additive for aluminum alloy production and preparation method thereof

Abstract

The invention provides an iron element additive for aluminum alloy production and a preparation method thereof, and belongs to the technical field of additives for aluminum alloy processing. The preparation method provided by the invention comprises the following steps: fully mixing magnesium chloride and potassium chloride, dissolving, cooling and preserving heat to obtain liquid molten salt; adding atomized iron powder, and uniformly distributing the atomized iron powder in the liquid molten salt to obtain a melt; and casting and molding the melt, and cooling to obtain the iron element additive. The obtained iron element additive has low requirement on the temperature of molten aluminum, and can be quickly dissolved and quickly absorbed after being added into the molten aluminum.

Description

Technical Field

[0001] The invention belongs to the technical field of additives for aluminum alloy processing, and specifically relates to an iron element additive for aluminum alloy production and a preparation method thereof. Background Art

[0002] In aluminum alloys, iron is generally added in the form of aluminum-iron master alloy or iron additives due to its high melting point. Currently, iron additives on the market are mainly composed of iron powder, flux and binder, and the commonly used flux is fluoride salt, chloride salt, aluminum powder, etc. For example, the Chinese invention patent with application number 201510543046.2 discloses a cake or rugby ball shape mainly composed of iron powder, aluminum powder and flux. The iron powder and aluminum powder are crushed under the protection of inert gas, and also include surfactants. The mass percentages of each component are: iron powder 90%-98%, aluminum powder 0-9.48%, flux 0.01%-5%, surfactant 0.5%-2%, and the density range of the above components after pressing is: 2.8~5.0g / cm 3 ; The flux can be sodium hexafluoroaluminate, sodium chloride, potassium chloride, sodium fluoride, potassium fluoride, sodium sulfate, sodium carbonate. This type of aluminum additive absorbs slowly, and although the fluoride salt additive has a high absorption rate, the general use temperature needs to reach 730°C. However, as the temperature rises, the aluminum melt absorbs hydrogen seriously, and the quality of the melt will decrease. It is urgent to develop an iron element additive that can dissolve quickly at low temperatures. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an iron element additive for aluminum alloy production which can be quickly dissolved at low temperature and a preparation method thereof.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing an iron element additive for aluminum alloy production, comprising the following steps: S1, fully mixing magnesium chloride and potassium chloride, then dissolving, then cooling and keeping warm to obtain liquid molten salt; S2, adding atomized iron powder to the liquid molten salt, and evenly distributing the atomized iron powder in the liquid molten salt to obtain a melt; S3, casting the melt into a shape, and obtaining the iron element additive after cooling.

[0005] An iron element additive for aluminum alloy production is prepared by the above-mentioned preparation method.

[0006] The beneficial effects of the present invention are as follows: the present invention generates a mixture of K2MgCl4 and K3MgCl7 by converting MgCl2 and KCl, and the mixture of K2MgCl4 and K3MgCl7 has a low melting point, and can be made into an additive without adding a co-solvent or a binder and used in the production of aluminum alloys. When the additive is used in the production of aluminum alloys, the temperature requirement for aluminum liquid is low, and the additive can be quickly dissolved and absorbed after being added to the aluminum liquid. DETAILED DESCRIPTION

[0007] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes.

[0008] A method for preparing an iron element additive for aluminum alloy production comprises the following steps: S1, fully mixing magnesium chloride and potassium chloride, then dissolving, then cooling and keeping warm to obtain liquid molten salt; S2, adding atomized iron powder to the liquid molten salt, and evenly distributing the atomized iron powder in the liquid molten salt to obtain a melt; S3, casting the melt into a shape, and obtaining the iron element additive after cooling.

[0009] From the above description, it can be seen that the beneficial effects of the present invention are: the preparation method provided by the present invention first uses MgCl2 and KCl to prepare a mixture of K2MgCl4 and K3MgCl7, the mixture has a low melting point of about 430°C, and then is fully and evenly mixed with atomized iron powder and cast into shape, and a dense surface is obtained by controlling the cooling rate to prevent it from absorbing moisture quickly, thereby obtaining an iron element additive. The preparation method provided by the present invention can prepare an iron element additive that can be quickly dissolved in 710°C aluminum liquid and can reach an absorption rate of 98~100% in about 10 minutes, while the iron element additives on the market can only reach a final absorption rate of 80~95% at about 740°C aluminum liquid. At the same time, the preparation method provided by the present invention can achieve quality control of the iron element additive through strict control of the process, so that the weight deviation of the pressed block is ±5g, and the density of the pressed block is 4.5~5.5g / cm 3 .

[0010] Furthermore, the mass ratio of magnesium chloride to potassium chloride in S1 is 40-50:60-50, preferably 54:46.

[0011] Furthermore, the dissolution temperature in S1 is 700-800° C. The temperature in S1 is lowered to 450-500° C. The holding time in S1 is 20-40 min.

[0012] Furthermore, the particle size of the atomized iron powder satisfies: +80 mesh ≤ 10%, 80~140 mesh ≥ 30%, 140~200 mesh ≥ 50%, -200 mesh ≤ 10%. The fluidity of the atomized iron powder is ≥ 1.6g / s. From the above description, it can be seen that +80 mesh means that it can pass through 80 mesh, that is, it is smaller than 80 mesh; by controlling the particle size of the atomized iron powder, its fluidity can be controlled, and then the weight of the briquette can be controlled within ±5g, and the density can be controlled within 4.5~5.5g / cm 3 , ensuring the uniformity of product quality.

[0013] Furthermore, the iron content in the atomized iron powder is 99.3-99.9%.

[0014] Furthermore, the cooling rate is 10-30°C / min.

[0015] Furthermore, the shape of the casting can be a conventional pancake shape or any other desired special shape. The iron element additive is packed in aluminum foil and then packed in a carton.

[0016] An iron element additive for aluminum alloy production is prepared by any of the above preparation methods.

[0017] Embodiment 1: A method for preparing an iron element additive for aluminum alloy production comprises the following steps: S1, smelting: weigh magnesium chloride and potassium chloride in a mass ratio of 45:55, mix them thoroughly in a V-shaped stirring tank, then put the mixed salt into a medium frequency furnace, heat it to 780°C to dissolve it, then reduce the temperature to 500°C and keep it warm for 30 minutes to obtain liquid molten salt; S2, adding powder and mixing: adding atomized iron powder with an Fe content of 99.5% to the liquid molten salt obtained in S1, stirring by electromagnetic induction in a medium frequency furnace, and stirring with argon gas for 0.5h to make the atomized iron powder evenly distributed in the liquid molten salt to obtain a melt; Among them, the atomized iron powder meets the following requirements: particle size +80 mesh ≤ 10%, 80-140 mesh ≥ 30%, 140-200 mesh ≥ 50%, -200 mesh ≤ 10%; fluidity ≥ 1.6 g / s; S3, casting: casting the melt obtained above into a round cake with a diameter of 30 mm, and obtaining an iron element additive after cooling; wherein the cooling rate is controlled at 25-30°C / min; S4. Packaging: The cake-shaped iron element additive cooled to room temperature is packed with aluminum foil and put into a carton.

[0018] Embodiment 2: S1, smelting: weigh magnesium chloride and potassium chloride in a mass ratio of 40:60, mix them thoroughly in a V-shaped stirring tank, then put the mixed salt into a medium frequency furnace, heat it to 800°C to dissolve it, then reduce the temperature to 480°C and keep it warm for 25 minutes to obtain liquid molten salt; S2, adding powder and mixing: adding atomized iron powder with an Fe content of 99.3% to the liquid molten salt obtained in S1, stirring by electromagnetic induction in a medium frequency furnace, and stirring with argon gas for 1 hour to make the atomized iron powder evenly distributed in the liquid molten salt to obtain a melt; Among them, the atomized iron powder meets the following requirements: particle size +80 mesh ≤ 10%, 80-140 mesh ≥ 30%, 140-200 mesh ≥ 50%, -200 mesh ≤ 10%; fluidity ≥ 1.6 g / s; S3, casting: casting the melt obtained above into a round cake with a diameter of 60 mm, and obtaining an iron element additive after cooling; wherein the cooling rate is controlled at 20-25°C / min; S4. Packaging: The cake-shaped iron element additive cooled to room temperature is packed with aluminum foil and put into a carton.

[0019] Embodiment three: S1, smelting: weigh magnesium chloride and potassium chloride in a mass ratio of 48:52, mix them thoroughly in a V-shaped stirring tank, then put the mixed salt into a medium frequency furnace, heat it to 750°C to dissolve it, then reduce the temperature to 460°C and keep it warm for 20 minutes to obtain liquid molten salt; S2, adding powder and mixing: adding atomized iron powder with an Fe content of 99.8% to the liquid molten salt obtained in S1, stirring by electromagnetic induction in a medium frequency furnace, and stirring with argon gas for 0.6h to make the atomized iron powder evenly distributed in the liquid molten salt to obtain a melt; Among them, the atomized iron powder meets the following requirements: particle size +80 mesh ≤ 10%, 80-140 mesh ≥ 30%, 140-200 mesh ≥ 50%, -200 mesh ≤ 10%; fluidity ≥ 1.6 g / s; S3, casting: casting the melt obtained above into a round cake with a diameter of 90 mm, and obtaining an iron element additive after cooling; wherein the cooling rate is controlled at 10-15°C / min; S4. Packaging: The cake-shaped iron element additive cooled to room temperature is packed with aluminum foil and put into a carton.

[0020] Embodiment 4: S1, smelting: weigh magnesium chloride and potassium chloride in a mass ratio of 50:50, mix them thoroughly in a V-shaped stirring tank, then put the mixed salt into a medium frequency furnace, heat it to 720°C to dissolve it, then reduce the temperature to 450°C and keep it warm for 40 minutes to obtain liquid molten salt; S2, adding powder and mixing: adding atomized iron powder with an Fe content of 99.6% to the liquid molten salt obtained in S1, stirring by electromagnetic induction in a medium frequency furnace, and stirring with argon gas for 0.8h to make the atomized iron powder evenly distributed in the liquid molten salt to obtain a melt; Among them, the atomized iron powder meets the following requirements: particle size +80 mesh ≤ 10%, 80-140 mesh ≥ 30%, 140-200 mesh ≥ 50%, -200 mesh ≤ 10%; fluidity ≥ 1.6 g / s; S3, casting: casting the melt obtained above into a block shape, and obtaining the iron element additive after cooling; wherein the cooling rate is controlled at 15-20°C / min; S4. Packaging: The cube-shaped iron element additive cooled to room temperature is packed with aluminum foil and put into a carton.

[0021] Comparative Example 1: A method for preparing an iron element additive for aluminum alloy production comprises the following steps: S1. Mix magnesium chloride, potassium chloride and atomized iron powder of the same proportion and source (manufacturer model) as in Example 1 by a V-type mixer, and then press them into blocks by a 125t automatic horizontal hydraulic press to obtain an iron element additive.

[0022] The iron element additives obtained in Examples 1 to 4 and Comparative Example 1 were tested, and the results are shown in Table 1.

[0023] Table 1

[0024] In summary, the preparation method of the iron element additive for aluminum alloy production provided by the present invention can make the additive without adding a solvent and use it in the production of aluminum alloy. The obtained iron element additive can be dissolved at a lower temperature and can be quickly absorbed. At 710°C, the absorption rate in 10 minutes can reach 98~100%.

[0025] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing an iron element additive for aluminum alloy production, characterized in that: The following steps are involved: S1, fully mixing magnesium chloride and potassium chloride, then dissolving, then cooling and keeping warm to obtain liquid molten salt; S2, adding atomized iron powder to the liquid molten salt, and evenly distributing the atomized iron powder in the liquid molten salt to obtain a melt; S3, casting the melt into a shape, and obtaining the iron element additive after cooling.

2. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The mass ratio of magnesium chloride to potassium chloride in S1 is 40-50:60-50.

3. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The dissolution temperature in S1 is 700~800℃.

4. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: In S1, the temperature is lowered to 450~500℃.

5. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The insulation time in S1 is 20 to 40 minutes.

6. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The particle size of the atomized iron powder meets the following requirements: +80 mesh ≤ 10%, 80-140 mesh ≥ 30%, 140-200 mesh ≥ 50%, -200 mesh ≤ 10%.

7. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The fluidity of the atomized iron powder is ≥1.6 g / s.

8. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The iron content in the atomized iron powder is 99.3-99.9%.

9. The method for preparing the iron element additive for aluminum alloy production according to claim 1, characterized in that: The cooling rate in S3 is 10~30℃ / min.

10. An iron element additive for aluminum alloy production, characterized in that: The method is prepared according to any one of claims 1 to 9.

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