Aluminum-strontium alloy material and preparation method thereof

Abstract

The invention provides an aluminum-strontium alloy material and a preparation method thereof. The preparation method comprises the following steps: S1, mixing strontium fluoride and a fluxing agent to obtain a villiaumite mixture; s2, the villiaumite mixture and molten aluminum are mixed for alloying, and aluminum-strontium alloy liquid is obtained; and S3, the aluminum-strontium alloy liquid is subjected to degassing, refining and rolling treatment, and the aluminum-strontium alloy material is obtained. According to the technical scheme, strontium fluoride (F2Sr) serves as the raw material, the raw material is pure, and in the production process, due to the fact that strontium fluoride and aluminum can be smelted at the low temperature, the defect that the oxide content exceeds the standard due to the high temperature is effectively overcome. And on the other hand, the aluminum-strontium alloy material is prepared through rolling treatment, production equipment can be a continuous casting and continuous rolling machine, automatic production can be achieved conveniently, the yield is large, the labor intensity is low, and the production cost is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of metal materials, and in particular, to an aluminum-strontium alloy material and a preparation method thereof. Background Art

[0002] Aluminum-silicon casting alloys are widely used in various fields of the national economy. In order to improve the mechanical properties of aluminum-silicon casting alloys, modification treatment is often carried out on them. Aluminum-strontium alloy can effectively refine eutectic silicon and primary silicon in the alloy and improve the mechanical properties of the alloy. Therefore, aluminum-strontium alloy is a very excellent modifier.

[0003] Castings modified with strontium have excellent mechanical properties. Especially after heat treatment, the alloy has good fluidity and seawater corrosion resistance, and can significantly reduce defects such as shrinkage cavities and misruns.

[0004] Aluminum-strontium alloy is mainly used in the production of automotive aluminum alloy wheels. It has become a new variety of aluminum processing with good development prospects.

[0005] The traditional process for producing aluminum-strontium alloy uses metallic strontium or celestine as raw materials. When using celestine to produce aluminum-strontium alloy, a large number of fine ore particles are difficult to completely separate from the aluminum liquid during the production process. These ore particles are doped in the alloy, reducing the modification effect of the aluminum-strontium alloy.

[0006] In some current processes, when using metallic strontium to produce aluminum-strontium alloy, the melting temperature needs to be maintained at 850 - 1000 °C. Such a high-temperature production environment is prone to generating a large amount of metal oxides. These refractory oxides are entrained in the alloy, affecting the purity of the finished product. Moreover, the finished product of aluminum-strontium alloy is in the shape of a waffle ingot, which requires manual casting, resulting in high labor intensity and low production efficiency.

[0007] In view of the above situation, there is an urgent need to develop a method to improve the quality of aluminum-strontium alloy and simplify the preparation process to meet the market demand for aluminum-strontium alloy. Summary of the Invention

[0008] The main object of the present invention is to provide an aluminum-strontium alloy material and a preparation method thereof to solve the problems of high impurity content and complex preparation process of aluminum-strontium alloy in the prior art.

[0009] To achieve the above object, according to one aspect of the present invention, there is provided a preparation method of an aluminum-strontium alloy material, the preparation method comprising: Step S1, mixing strontium fluoride and a flux to obtain a fluoride salt mixture; Step S2, mixing the fluoride salt mixture with aluminum liquid for alloying to obtain an aluminum-strontium alloy liquid; Step S3, performing degassing, refining, and rolling treatment on the aluminum-strontium alloy liquid to obtain an aluminum-strontium alloy material.

[0010] Further, the flux includes any one or more of chloride fluxes and cryolite powder;

[0011] The mass ratio of strontium fluoride to the flux is 10:(1-2).

[0012] Further, the mass ratio of strontium fluoride to the aluminum liquid is 1:(11-12).

[0013] Further, the temperature of the alloying treatment is 750°C - 780°C.

[0014] Further, the aluminum liquid is obtained after impurity removal and refining; preferably, the temperature of the aluminum liquid is 750°C - 780°C;

[0015] Preferably, the time for impurity removal and refining is 10 - 20 min.

[0016] Further, the impurity removal and refining includes: using an inert gas as a carrier to spray a refining agent into the aluminum liquid through a spraying device. By weight percentage, the refining agent includes a mixture of 20% - 30% potassium chloride, 20% - 30% sodium chloride, 20% - 30% magnesium chloride, 20 - 30% aluminum fluoride, and 20 - 30% calcium fluoride;

[0017] Preferably, the refining agent is evenly sprayed into the interior of the melt using the spraying device, stirred evenly, left standing for 10 - 15 minutes, and then the slag is skimmed off;

[0018] Preferably, the addition amount of the refining agent is 0.07% - 0.14% of the mass of the aluminum liquid.

[0019] Further, the fluoride salt mixture includes a first fluoride salt mixture and a second fluoride salt mixture. The first fluoride salt mixture accounts for 40% - 60% of the fluoride salt mixture, and the second fluoride salt mixture accounts for 40% - 60% of the fluoride salt mixture. The step S2 includes:

[0020] The first step of alloying: Under stirring conditions, add the first fluoride salt mixture to the aluminum liquid. After the feeding is completed, remove the fluoride salt slag water layer above to obtain the first-step alloy liquid;

[0021] The second step of alloying: Under stirring conditions, add the second fluoride salt mixture to the first-step alloy liquid. After the feeding is completed, perform second stirring and heat preservation treatment in sequence, remove the fluoride salt slag water layer above to obtain the aluminum-strontium alloy liquid; preferably, the second step of alloying further includes: adding a refining agent after removing the fluoride salt slag water layer above to remove the impurities on the surface.

[0022] Further, the stirring method in the first step of alloying and / or the second step of alloying is bottom stirring;

[0023] In the first step of alloying, the feeding time of the first fluoride salt mixture is 10 - 15 min;

[0024] In the second step of alloying, the feeding time of the second fluoride salt mixture is 10 - 20 min, the stirring time of the second stirring is 10 - 15 min, and the heat preservation time is 10 - 30 min.

[0025] Furthermore, the casting temperature of the rolling treatment is 780 - 800 °C, the casting speed is 3 - 4 t / h, and the rolling-in temperature is 450 - 500 °C.

[0026] In order to achieve the above object, according to one aspect of the present invention, an aluminum strontium alloy material is provided, and this aluminum strontium alloy material is prepared by the preparation method of any one of the above aluminum strontium alloy materials.

[0027] Applying the technical solution of the present invention, using strontium fluoride (F 2 Sr) as the raw material, the raw material is strontium fluoride, and the raw material is relatively pure. During the production process, and because strontium fluoride and aluminum can be melted at a relatively low temperature, the disadvantage of excessive oxide content caused by high temperature is effectively reduced. On the other hand, the aluminum strontium alloy material of the present application is made by rolling treatment, and the production equipment can be a continuous casting and rolling mill, which is convenient for realizing automated production, has a large output, low labor intensity, and effectively reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The specification drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 Shows the aluminum strontium alloy rod product according to Embodiment 1 of the present invention;

[0030] Figure 2 Shows the fracture microstructure of the aluminum strontium alloy rod according to Embodiment 1 of the present invention;

[0031] Figure 3 Shows the aluminum strontium alloy ingot according to Comparative Example 1 of the present invention;

[0032] Figure 4 Shows the fracture microstructure of the aluminum strontium alloy ingot according to Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0034] As analyzed in the background art of the present application, there are problems of high impurity content and complex preparation process in the prior art aluminum strontium alloy. To solve this problem, the present application provides an aluminum strontium alloy material and a preparation method thereof.

[0035] According to a typical embodiment of the present application, a preparation method of an aluminum strontium alloy material is provided. The preparation method includes: Step S1, mixing strontium fluoride and a flux to obtain a fluoride salt mixture; Step S2, mixing the fluoride salt mixture with molten aluminum for alloying to obtain an aluminum strontium alloy liquid; Step S3, degassing, refining and rolling the aluminum strontium alloy liquid to obtain an aluminum strontium alloy material.

[0036] The present application uses strontium fluoride (F 2 Sr) as a raw material. The raw material is strontium fluoride and is relatively pure. During the production process, and because strontium fluoride and aluminum can be melted at a relatively low temperature, it effectively reduces the disadvantage of excessive oxide content caused by high temperature. On the other hand, the aluminum strontium alloy material of the present application is made by rolling treatment. The production equipment can be a continuous casting and rolling mill, which is convenient for realizing automated production, has a large output and low labor intensity, and effectively reduces the production cost.

[0037] The above-mentioned flux can be selected from the prior art. In some embodiments of the present application, the flux includes any one or more of chloride salt fluxes and cryolite powder. Among them, the chloride salt fluxes include potassium chloride, sodium chloride, magnesium chloride, hexachloroethane, rare earth fluorides, etc., but are not limited thereto.

[0038] In some embodiments of the present application, the mass ratio of strontium fluoride to the flux is 10:(1-2), specifically it can be 10:1, 10:1.2, 10:1.5, 10:1.8, 10:2, etc., which has a relatively significant effect on improving the solubility of strontium in molten aluminum and enhancing the preparation efficiency of the aluminum strontium alloy.

[0039] In some preferred embodiments of the present application, the above-mentioned flux includes cryolite powder and chloride salt fluxes, which is for reducing the melting point temperature of strontium fluoride, enhancing the fluidity of molten aluminum, reducing component segregation, enhancing the solubility of strontium element in molten aluminum, and promoting the alloying process. Especially when the flux includes both cryolite powder and chloride salt fluxes, it has a relatively significant effect on enhancing the fluidity of molten aluminum and improving the quality of the aluminum strontium alloy material.

[0040] In some typical embodiments of the present application, strontium fluoride, cryolite powder and the flux are added to a mixer and mixed for 20-60 min to make a fluoride salt mixture.

[0041] In the above step S2, the above fluorine salt mixture is mixed with molten aluminum liquid for alloying to prepare aluminum-strontium alloy liquid. The mixing ratio of the fluorine salt mixture and the aluminum liquid can be determined according to the composition requirements of the aluminum-strontium alloy material, and the present application has no particular restrictions on this. In some embodiments of the present application, the mass ratio of strontium fluoride in the above fluorine salt mixture to the aluminum liquid is 1:(11-12).

[0042] In some typical embodiments of the present application, the temperature of the alloying treatment is 750°C-780°C. At this temperature, strontium fluoride can be converted into strontium element to form aluminum-strontium alloy liquid, and the excessive oxide content caused by high temperature is effectively reduced.

[0043] In some embodiments of the present application, the above-mentioned aluminum liquid is obtained after impurity removal and refining, so that it has a higher purity, thereby further reducing the impurity content in the aluminum strontium alloy. In some embodiments of the present application, when mixed with strontium fluoride, the temperature of the aluminum liquid is 750°C to 780°C, which is conducive to the alloying of the present application. In some preferred embodiments of the present application, the time of the above-mentioned impurity removal and refining is 10 to 20 minutes.

[0044] In some preferred embodiments of the present application, the above-mentioned impurity removal and refining includes: spraying a refining agent into the aluminum liquid through a blowing device using an inert gas as a carrier, and the refining agent includes any one or more of sodium chloride, potassium chloride, magnesium chloride, calcium fluoride, and aluminum fluoride.

[0045] In some preferred embodiments of the present application, the refining agent includes a mixture of 20%-30% potassium chloride, 20%-30% sodium chloride, 20%-30% magnesium chloride, 20-30% aluminum fluoride, and 20-30% calcium fluoride, which has a particularly significant effect on removing impurities and improving purity of the system of the present application, and reduces the oxide content in the aluminum-strontium alloy material. As an example, the refining agent is a solid particle, but is not limited thereto.

[0046] When the refining agent is sprayed into the aluminum melt by inert gas, the solid particles can quickly melt into droplets. Since the density of these droplets is lower than that of the aluminum melt, the surface tension with the slag inclusions (oxides, borides and carbides) is small, and they have a strong ability to wet and adsorb the slag inclusions; when the slag inclusions are adsorbed by the refining agent droplets, they float up and are removed from the melt. At the same time, after the refining agent droplets float up, they form a liquid layer covering the surface of the aluminum melt, which can also reduce the oxidation and burning of the aluminum melt, thus playing a good role in removing slag. On the other hand, after the refining agent enters the aluminum melt, it will react with the alkali metal elements Na and Ca, release magnesium atoms into the aluminum alloy melt, and at the same time bring the alkali metal elements Na, Ca and Li absorbed by the reaction to the surface of the aluminum melt, thereby playing a role in removing alkali metals.

[0047] In some embodiments of the present application, in order to better play the role of the refining agent in removing slag and impurities, the refining agent is evenly sprayed into the melt by a blowing device, stirred evenly, and then slag is removed after standing for 10 to 15 minutes. In some embodiments of the present application, the temperature of the aluminum liquid when the refining agent is added is 720°C to 800°C.

[0048] In some preferred embodiments of the present application, the amount of refining agent added is 0.07% to 0.14% of the mass of the aluminum liquid, which has a significant effect on removing slag and impurities from the aluminum liquid, making the aluminum-strontium alloy liquid purer.

[0049] In some typical embodiments of the present application, the above-mentioned fluoride salt mixture includes a first fluoride salt mixture and a second fluoride salt mixture, the first fluoride salt mixture accounts for 40% to 60% of the fluoride salt mixture, and the second fluoride salt mixture accounts for 40% to 60% of the fluoride salt mixture, and step S2 includes: a first step of alloying: under stirring, the first fluoride salt mixture is added to the aluminum liquid, and after the addition is completed, the fluoride salt slag water layer on the top is removed to obtain the first step alloy liquid; a second step of alloying: under stirring, the second fluoride salt mixture is added to the first step alloy liquid, and after the addition is completed, a second stirring and insulation treatment are performed in sequence to remove the fluoride salt slag water layer on the top to obtain an aluminum strontium alloy liquid.

[0050] Adding the fluoride salt mixture into the aluminum liquid for alloying in multiple times can promote the complete conversion of strontium fluoride into strontium element and further improve the purity of the aluminum-strontium alloy.

[0051] In some preferred embodiments, the stirring method in the first alloying step and / or the second alloying step is bottom stirring.

[0052] In some embodiments of the present application, in the first alloying step, the first fluoride salt mixture is added for 10 to 15 minutes. For example, a rotary propeller feeder is used to evenly add the first fluoride salt mixture into the aluminum liquid.

[0053] In some embodiments of the present application, in the second step of alloying, the addition time of the second fluoride salt mixture is 10 to 20 minutes, the second stirring time is 10 to 15 minutes, and the insulation time is 10 to 30 minutes, which is beneficial to further improve the purity of the aluminum strontium alloy. In some embodiments of the present application, the second step of alloying also includes: adding a refining agent after removing the upper fluoride salt slag water layer, removing surface impurities, and further removing oxides, borides, carbides, and alkali metal elements Na, Ca and Li in the alloy liquid. The type of refining agent added in this step can refer to the refining agent added in the above-mentioned aluminum liquid impurity removal and refining process, and will not be repeated here. Preferably, the amount of refining agent added in the second step of alloying is 0.03% to 0.1% of the weight of the aluminum liquid, preferably 0.05%.

[0054] In the above step S3, the aluminum strontium alloy liquid prepared in the above step is degassed and refined. Degassing and refining can adopt methods in the prior art, and this application has no limitation in this regard. In some embodiments of this application, the degassing and refining process includes: transferring the aluminum strontium alloy liquid to a refining furnace through a transfer ladle, turning on the power of the induction electric furnace, and maintaining the temperature of the aluminum strontium alloy liquid at 750-780°C. Use a rotary degasser to introduce argon for degassing and refining. After refining for 20 minutes, stop the furnace and remove the scum on the surface of the alloy.

[0055] In some embodiments of this application, the casting temperature for rolling treatment is 780-800°C, the casting speed is 3-4 t / h, and the rolling-in temperature is 450-500°C. In some embodiments of this application, the rolled aluminum strontium alloy material is an aluminum strontium alloy rod.

[0056] In some typical embodiments of this application, the preparation method of the above aluminum strontium alloy material includes the following steps: 1. Weigh strontium fluoride, cryolite powder, and a flux (chloride salts), and add the three in proportion to a mixer and mix for 30 minutes to make a fluoride salt mixture. 2. Weigh aluminum ingots by weight, put the aluminum ingots into a variable-frequency induction electric furnace and heat up to 800-850°C, and use argon as a carrier to spray a particulate refining agent into the aluminum liquid through a spraying device for impurity removal and refining. The refining time is 10-15 minutes. 3. First alloying: Turn on the electromagnetic stirring, the stirring method is bottom stirring, and use a rotary propelling feeder to evenly add part of the fluoride salt mixture into the aluminum liquid. The feeding time is 10-15 minutes. During the process, keep the temperature of the aluminum water at 750-780°C. After the feeding is completed, remove the fluoride salt slag water layer above the furnace to obtain aluminum strontium alloy liquid. 4. Second alloying: ① Turn on the electromagnetic stirring of the induction furnace, the stirring method is bottom stirring, and control the stirring voltage at 280-300V. Add the remaining fluoride salt mixture evenly into the aluminum liquid through the feeder, and control the feeding time at 20 minutes; ② Adjust the power of the induction electric furnace to keep the temperature of the aluminum water at 750-780°C, and stir electromagnetically for 10-15 minutes; ③ Adjust the induction electric furnace to the heating mode, keep warm for 10 minutes, remove the fluoride salt slag water layer above the aluminum water, add a refining agent into the alloy liquid, stir evenly, and then remove the impurities on the surface. 5. Degassing and refining: Transfer the alloy liquid to a refining furnace through a transfer ladle, turn on the power of the induction electric furnace, and maintain the temperature of the alloy liquid at 750-780°C. Use a rotary degasser to introduce argon for degassing and refining. After refining for 20 minutes, stop the furnace and remove the scum on the surface of the alloy. 6. Rolling: The casting temperature is 780-800°C, the casting speed is 3-4 t / h, adjust the cooling system to control the rolling temperature, the rolling-in temperature is 450-500°C, and roll it into an aluminum strontium alloy rod.

[0057] According to another typical embodiment of the present application, an aluminum strontium alloy material is provided, which is prepared by the preparation method of any one of the above aluminum strontium alloy materials.

[0058] The above aluminum strontium alloy material is prepared using strontium fluoride as a raw material, and the raw materials are relatively pure. Moreover, during the production process, since strontium fluoride and aluminum can be melted at a relatively low temperature, the drawback of excessive oxide content caused by high temperature is effectively reduced. On the other hand, the aluminum strontium alloy material of the present application is made by rolling treatment, and the production equipment can be a rolling mill, which is convenient for realizing automated production, has a large output, low labor intensity, and effectively reduces the production cost.

[0059] In some embodiments of the present application, the above aluminum strontium alloy material is an aluminum strontium alloy rod, which is convenient for application and has better market prospects.

[0060] The beneficial effects that the present application can achieve will be further described below in conjunction with examples and comparative examples.

[0061] Example 1

[0062] 1. Weigh 90% of strontium fluoride, 5% of cryolite powder, and 5% of a flux (a mixture of 25% potassium chloride, 25% sodium chloride, 20% magnesium chloride, 20% aluminum fluoride, and 10% calcium fluoride). Add the three to a mixer and mix for 30 minutes to make a fluoride salt mixture.

[0063] 2. Melting: Weigh aluminum ingots (purity 99.7%). Put the aluminum ingots into a variable-frequency induction electric furnace and heat up to 750 - 780 °C. Use argon as a carrier to spray the SATA-GF-M16 environmentally friendly molten particle refining agent into the aluminum liquid through a spraying device for impurity removal and refining. The addition amount is 0.04% of the melt volume, and the refining time is 15 minutes.

[0064] 3. First-step alloying: Turn on the electromagnetic stirring, with the stirring method being bottom stirring. According to the mass ratio of the total addition amount of the fluoride salt mixture to the aluminum liquid of 1:9, use a rotary propelling feeder to uniformly add 50% of the fluoride salt mixture into the aluminum liquid. The feeding time is 15 minutes. During the process, keep the aluminum water temperature at 750 - 780 °C. After the feeding is completed, pour out the fluoride salt slag water layer above the furnace to obtain aluminum strontium alloy liquid.

[0065] 4. Second-step alloying:

[0066] ① Turn on the electromagnetic stirring of the induction furnace, with the stirring method being bottom stirring. Control the stirring voltage at 280 - 300 V, and uniformly add the remaining fluoride salt mixture into the aluminum liquid through the feeder. The feeding time is controlled at 20 minutes.

[0067] ② Adjust the power of the induction electric furnace to keep the aluminum water temperature at 750 - 780 °C, and perform electromagnetic stirring for 15 minutes.

[0068] ③Adjust the induction furnace to the heating mode, keep it warm for 10 min, pour out the fluoride salt slag water layer above the molten aluminum, add SATA-GF-M16 environmentally friendly molten particulate refining agent into the alloy liquid, with the addition amount being 0.04% of the melt amount. After uniform stirring, remove the impurities on the surface.

[0069] 5. Degassing and refining: Transfer the alloy liquid to the refining furnace through a transfer ladle, turn on the power of the induction furnace, and keep the temperature of the alloy liquid at 750 - 780 °C. Use a rotary degasser to introduce argon for degassing and refining. After 20 min of refining, stop the furnace and remove the floating slag on the surface of the alloy.

[0070] 6. Rolling: The casting temperature is 780 - 800 °C, the casting speed is 3 t / h, adjust the cooling system to control the rolling temperature, the inlet rolling temperature is 450 - 500 °C, and roll it into an aluminum strontium alloy rod.

[0071] The produced aluminum strontium alloy rod is as Figure 1 shown, and its fracture structure is as Figure 2 shown. It can be seen from Figure 2 that the fracture structure of the aluminum strontium alloy rod is dense, without obvious oxide impurities and pores.

[0072] Example 2

[0073] The difference from Example 1 is that: in the first step of alloying feeding in Step 3, the temperature of the molten aluminum is 780 - 800 °C; in the second step of the alloying process, the temperature of the alloy liquid is 780 - 800 °C.

[0074] There are a small number of pores in the fracture of the prepared aluminum strontium alloy rod, and there are a large number of oxide inclusions.

[0075] Example 3

[0076] The difference from Example 1 is that: in the first step of alloying feeding in Step 3, the temperature of the molten aluminum is 700 - 720 °C; in the second step of the alloying process, the temperature of the alloy liquid is 700 - 720 °C.

[0077] The fracture of the prepared aluminum strontium alloy rod contains a large number of oxide inclusions, and there are black salt spots on the surface of the alloy.

[0078] Example 4

[0079] The difference from Example 1 is that: the casting temperature in Step 6 is (700 ± 10) °C.

[0080] The fracture of the prepared aluminum strontium alloy rod contains a small amount of oxide inclusions, and the alloy rod is easy to break, resulting in discontinuous production.

[0081] Example 5

[0082] The difference from Example 1 is that in Step 1, no cryolite powder was added, and the addition amount of the chloride flux was 10%.

[0083] The chemical composition of strontium in the prepared aluminum-strontium alloy rod was 4.0%, the recovery rate of strontium element was low, and the aluminum-strontium alloy had composition segregation.

[0084] Example 6

[0085] The difference from Example 1 is that in Step 2, no SATA-GF-M16 environmentally friendly molten granular refining agent was added.

[0086] The fracture of the prepared aluminum-strontium alloy rod had Al 2 O 3 oxide inclusions, and some small pores were distributed.

[0087] Example 7

[0088] 1. Weigh 90% of strontium fluoride, 5% of cryolite powder, and 5% of flux (a mixture of 25% potassium chloride, 25% sodium chloride, 20% magnesium chloride, 20% aluminum fluoride, and 10% calcium fluoride) by mass fraction, and add the three to a mixer and mix for 30 min to make a fluoride salt mixture.

[0089] 2. Melting: Weigh aluminum ingots (purity 99.7%), put the aluminum ingots into a variable-frequency induction furnace and heat up to 750 - 780 °C, and use argon as a carrier to spray the SATA-GF-M16 environmentally friendly molten granular refining agent into the aluminum liquid through a spraying device for impurity removal and refining. The addition amount is 0.04% of the molten metal amount, and the refining time is 15 min.

[0090] 3. Alloying:

[0091] ① Turn on the electromagnetic stirring of the induction furnace. The stirring method is bottom stirring, and the stirring voltage is controlled at 280 - 300 V. According to the mass ratio of the total addition amount of the fluoride salt mixture to the aluminum liquid of 1:9, add all the fluoride salt mixture evenly into the aluminum liquid through a feeding machine, and the feeding time is controlled within 20 min.

[0092] ② Adjust the power of the induction furnace to keep the aluminum water temperature at 750 - 780 °C and stir electromagnetically for 15 min.

[0093] ③ Adjust the induction furnace to the heating mode, keep it warm for 10 min, pour out the fluoride salt slag water layer above the aluminum water, add the SATA-GF-M16 environmentally friendly molten granular refining agent into the alloy liquid, with the addition amount being 0.04% of the molten metal amount. After stirring evenly, remove the impurities on the surface.

[0094] 4. Degassing and refining: Transfer the molten alloy to the refining furnace through a transfer ladle, turn on the power of the induction furnace, and maintain the temperature of the molten alloy at 750 - 780 °C. Use a rotary degasser to introduce argon for degassing and refining. After 20 minutes of refining, stop the furnace and remove the scum on the surface of the alloy.

[0095] 5. Rolling: The casting temperature is 780 - 800 °C, the casting speed is 3 t / h, adjust the cooling system to control the rolling temperature, the entry rolling temperature is 450 - 500 °C, and roll into aluminum strontium alloy rods.

[0096] The fracture structure of the prepared aluminum strontium alloy rods is dense, with a small amount of oxide impurities and no pores.

[0097] Comparative Example 1

[0098] 1. Raw material preparation: Select relatively high-purity aluminum (purity 99.7%) and metallic strontium (purity 99%) as the basic raw materials. The aluminum is in the form of aluminum ingots or aluminum blocks. At the same time, prepare auxiliary materials such as refining agents.

[0099] 2. Melting aluminum: Put the aluminum raw materials into the furnace and heat to melt. At a temperature of about 700 - 750 °C, the aluminum can be completely melted into a liquid state to form molten aluminum.

[0100] 3. Adding strontium: When the aluminum is completely melted, under stirring conditions, slowly add metallic strontium to the molten aluminum. Make the strontium evenly dispersed in the molten aluminum under stirring conditions.

[0101] 4. Refining treatment: Add a refining agent for refining treatment to remove gases and impurities in the aluminum strontium alloy liquid. The refining time is about 15 - 30 minutes.

[0102] 5. Casting and forming: Pour the refined aluminum strontium alloy liquid into a pre-prepared mold for casting and forming.

[0103] This method has the following disadvantages: Severe oxidation of strontium, large loss, and difficult to control the utilization rate; Violent reaction, serious environmental pollution; Coarse structure of the master alloy, unstable modification effect; Difficult to store and transport the metal, etc.

[0104] The aluminum strontium alloy ingots produced in this comparative example are as Figure 3 shown, and its fracture structure is as Figure 4 shown. It can be seen from Figure 4 that the fracture structure of this aluminum strontium alloy ingot contains strip-shaped ore impurities, massive oxide impurities, and circular pores.

[0105] The main components other than aluminum in the aluminum strontium alloy materials prepared in the above examples and comparative examples are shown in Table 1 below.

[0106] Table 1

[0107]

[0108] It can be seen from the composition data of the aluminum-strontium alloy in Table 1 that the aluminum-strontium alloy produced by the method of the present application has a uniform composition, no segregation occurs, and meets the industry standards.

[0109] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: The present application uses strontium fluoride as the raw material, and the raw material is strontium fluoride, which is relatively pure. During the production process, since strontium fluoride and aluminum can be melted at a relatively low temperature, the disadvantage of excessive oxide content caused by high temperature is effectively reduced. On the other hand, the aluminum-strontium alloy material of the present application is made by rolling treatment, and the production equipment can be a rolling mill, which is convenient for realizing automated production, has a large output, low labor intensity, and effectively reduces the production cost.

[0110] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an aluminum-strontium alloy material, characterized in that: include: Step S1, mixing strontium fluoride and a flux to obtain a fluoride salt mixture; Step S2, mixing the fluoride salt mixture with aluminum liquid for alloying to obtain aluminum-strontium alloy liquid; Step S3, degassing, refining, and rolling the aluminum-strontium alloy liquid to obtain an aluminum-strontium alloy material.

2. The method for preparing the aluminum-strontium alloy material according to claim 1, characterized in that: The flux includes any one or more of chloride salt flux and cryolite powder; The mass ratio of the strontium fluoride to the flux is 10:(1-2).

3. The method for preparing the aluminum-strontium alloy material according to claim 1, characterized in that: The mass ratio of the strontium fluoride to the aluminum liquid is 1:(11-12).

4. The method for preparing the aluminum-strontium alloy material according to claim 1, characterized in that: The alloying treatment temperature is 750°C-780°C.

5. The method for preparing the aluminum-strontium alloy material according to claim 1, characterized in that: The aluminum liquid is obtained after impurity removal and refining; preferably, the temperature of the aluminum liquid is 750° C. to 780° C.; Preferably, the time for removing impurities and refining is 10 to 20 minutes.

6. The method for preparing the aluminum-strontium alloy material according to claim 5, characterized in that: The impurity removal refining comprises: spraying a refining agent into the aluminum liquid through a blowing device using an inert gas as a carrier, wherein the refining agent comprises a mixture of 20%-30% potassium chloride, 20%-30% sodium chloride, 20%-30% magnesium chloride, 20-30% aluminum fluoride, and 20-30% calcium fluoride in terms of weight percentage; Preferably, the refining agent is uniformly sprayed into the melt by the blowing device, stirred evenly, and then left to stand for 10 to 15 minutes before slagging; Preferably, the amount of the refining agent added is 0.07% to 0.14% of the mass of the aluminum liquid.

7. The method for preparing an aluminum-strontium alloy material according to claim 1, characterized in that: The fluoride salt mixture comprises a first fluoride salt mixture and a second fluoride salt mixture, the first fluoride salt mixture accounts for 40% to 60% of the fluoride salt mixture, and the second fluoride salt mixture accounts for 40% to 60% of the fluoride salt mixture, and the step S2 comprises: The first step of alloying: adding the first fluorine salt mixture to the aluminum liquid under stirring, and removing the fluorine salt slag water layer above after the addition is completed to obtain the first step alloy liquid; The second step of alloying: adding the second fluoride salt mixture to the first step alloy liquid under stirring conditions, and after the addition is completed, performing second stirring and heat preservation treatments in sequence to remove the upper fluoride salt slag water layer to obtain an aluminum strontium alloy liquid; preferably, the second step of alloying also includes: adding a refining agent after removing the upper fluoride salt slag water layer to remove surface impurities.

8. The method for preparing the aluminum-strontium alloy material according to claim 7, characterized in that: The stirring method in the first alloying step and / or the second alloying step is bottom stirring; In the first step of alloying, the first fluoride salt mixture is added for 10 to 15 minutes; In the second step of alloying, the feeding time of the second fluorine salt mixture is 10 to 20 minutes, the second stirring time is 10 to 15 minutes, and the heat preservation time is 10-30 minutes.

9. The method for preparing an aluminum-strontium alloy material according to claim 1, characterized in that: The casting temperature of the rolling process is 780-800°C, the casting speed is 3-4t / h, and the rolling temperature is 450-500°C.

10. An aluminum-strontium alloy material, characterized in that: The aluminum-strontium alloy material is prepared by the preparation method of the aluminum-strontium alloy material according to any one of claims 1 to 9.

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