Master alloy, preparation method and use thereof, and preparation method of reinforced alloy

Abstract

The present invention discloses a master alloy, a preparation method and use thereof, and a preparation method of a reinforced alloy. The master alloy of the present invention has the following composition: zAl‑xTiB 2 ‑yRE m O n ; Among them, RE represents rare earth element, x represents TiB 2 Parts by weight, y represents RE m O n The master alloy can improve the strength of aluminum-based materials.

Description

Technical Field

[0001] The present invention relates to an intermediate alloy, a preparation method and uses thereof, and a preparation method of a reinforced alloy. Background Art

[0002] Aluminum-based materials (metallic aluminum and aluminum alloys) have advantages such as low mass, good fluidity, and good corrosion resistance, but their strength still needs to be improved. Titanium diboride is a stable compound composed of titanium and boron, having a relatively high modulus, hardness, as well as good electrical conductivity, thermal conductivity, corrosion resistance, and thermal stability, and is an ideal particulate reinforcement phase. However, titanium diboride particles have problems such as uneven dispersion and poor wettability with the matrix in aluminum-based materials, and their strengthening effect on aluminum-based materials still needs to be enhanced.

[0003] CN113564402A discloses an Al-TiO 2 -C-xRE 2 O 3 composite refiner. First, Al powder, TiO 2 powder, and C powder are mixed evenly to obtain a mixed raw material A, and then rare earth oxide RE 2 O 3 powder is added to the mixed raw material A and mixed evenly to obtain a mixed raw material powder; the mixed raw material powder is pressed into a preform; the preform is placed in a corundum crucible, and the periphery of the preform is filled with Al 2 O 3 powder, and then the corundum crucible containing the preform is placed in a drying oven for drying; after the corundum crucible containing the preform is dried, it is transferred to a sintering furnace for sintering, and after sintering, it is cooled with the furnace to obtain an Al-TiO 2 -C-xRE 2 O 3 composite refiner. This method does not form an alloy, and it is a refiner, and its strengthening effect on the mechanical properties of aluminum-based materials is poor.

[0004] CN112011704A discloses a rare earth aluminum-titanium-boron grain refiner. The grain refiner includes: 1.0-10.0% of titanium, 0.5-5.0% of boron, 0.1-5.0% of rare earth, and the balance is aluminum. The grain refiner is prepared by the following method: after the raw materials are heated to melt the aluminum ingot, the melt temperature is controlled at 750-850 °C, and a mixed salt of potassium hexafluorotitanate and potassium hexafluoroborate is added for reaction; after stirring until the melt reaction is complete, slag is removed by skimming while maintaining the temperature, and sodium chloride, potassium chloride, cryolite, and rare earth oxide or rare earth fluoride and metallic calcium are added for reaction, and the reaction temperature is controlled at 1000-1100 °C; after stirring until the melt reaction is complete, refining is carried out, and after skimming the slag while maintaining the temperature, casting is carried out to obtain the rare earth aluminum-titanium-boron grain refiner. The rare earth aluminum-titanium-boron alloy is used as a grain refiner. Summary of the Invention

[0005] In view of this, an object of the present invention is to provide an intermediate alloy that can improve the mechanical strength of an aluminum-based material.

[0006] Another object of the present invention is to provide a method for preparing an intermediate alloy, and the intermediate alloy prepared by this method can improve the mechanical strength of an aluminum-based material.

[0007] Still another object of the present invention is to provide a use of the intermediate alloy.

[0008] Yet another object of the present invention is to provide a method for preparing a reinforced alloy. The reinforced alloy obtained by this method has high mechanical strength.

[0009] The above objects are achieved by the following technical solutions.

[0010] On the one hand, the present invention provides an intermediate alloy having the following composition:

[0011] zAl - xTiB 2 - yRE m O n ;

[0012] Wherein, RE represents a rare earth element, x represents the weight part of TiB 2 , y represents the weight part of RE m O n , z represents the weight part of Al, and m and n are determined according to the valence of RE;

[0013] Wherein, 1.0 ≤ x ≤ 20, 0.1 ≤ y ≤ 10, z = 100 - x - y.

[0014] According to the intermediate alloy of the present invention, preferably, the RE m O n is selected from one or more of La 2 O 3 , CeO 2 , Nd 2 O 3 , Y 2 O 3 , Er 2 O 3 .

[0015] According to the intermediate alloy of the present invention, preferably, the hydrogen content in the intermediate alloy ≤ 0.15 mL / 100 g.

[0016] On the other hand, the present invention provides a method for preparing the above intermediate alloy, including the following steps:

[0017] (1)Disperse rare earth oxides in the melt formed by the first salt solvent, and then cool to obtain a first precursor; crush the first precursor to obtain a first precursor powder;

[0018] (2)Disperse titanium dioxide and boron oxide in the melt formed by the second salt solvent, and then cool to obtain a second precursor; crush the second precursor to obtain a second precursor powder;

[0019] (3)React molten aluminum with the first precursor powder to obtain a first intermediate alloy liquid; react the first intermediate alloy liquid with the second precursor powder, and then remove the molten salt after the reaction to obtain a second intermediate alloy liquid; refine and degas the second intermediate alloy liquid, and then skim the slag to obtain an alloy liquid; shape the alloy liquid to obtain an intermediate alloy.

[0020] According to the preparation method of the present invention, preferably, the first salt solvent includes potassium chloride, sodium chloride and cryolite; the second salt solvent includes potassium chloride, sodium chloride and cryolite.

[0021] According to the preparation method of the present invention, preferably, in the first salt solvent, sodium chloride is 20-50 parts by weight, potassium chloride is 5-30 parts by weight, and cryolite is 40-80 parts by weight; in the second salt solvent, sodium chloride is 20-50 parts by weight, potassium chloride is 5-30 parts by weight, and cryolite is 40-80 parts by weight.

[0022] According to the preparation method of the present invention, preferably, the particle size of the first precursor powder ≤ 3 cm, and the particle size of the second precursor powder ≤ 3 cm; the molten aluminum reacts with the first precursor powder at 750-950 °C; use argon to refine and degas the second intermediate alloy liquid; use casting to shape, and the temperature of the alloy liquid is 700-850 °C.

[0023] On the other hand, the present invention provides the use of the above intermediate alloy in enhancing the mechanical strength of aluminum-based materials.

[0024] On the other hand, the present invention provides a preparation method of a reinforced alloy, including the following steps:

[0025] Form a reinforced alloy liquid by mixing the above intermediate alloy with an aluminum-containing substance; shape the reinforced alloy liquid to obtain a reinforced alloy;

[0026] Wherein, the aluminum-containing substance is selected from aluminum alloy, metallic aluminum or raw materials for forming aluminum alloy.

[0027] According to the preparation method of the present invention, preferably, it includes the following steps: melt the above intermediate alloy and the aluminum-containing substance to form a to-be-treated alloy liquid; use argon to refine and degas the to-be-treated alloy liquid, and then skim the slag to obtain a reinforced alloy liquid.

[0028] Since rare earth oxides in TiB2 A rare earth protective film is formed on the particle surface, making TiB 2 particles smaller, and TiB 2 particles have a lower tendency to agglomerate, improving the wettability between TiB 2 particles and the matrix alloy. TiB 2 particles and rare earth oxides can be evenly dispersed in the master alloy of the present invention, enhancing the strengthening effect of the master alloy on the aluminum-based material. The master alloy of the present invention has a low hydrogen content, which can reduce defects such as pores and inclusions in the master alloy or the strengthened alloy, as well as the formation of harmful phases such as coarse Al-Fe-Si, and improve the mechanical properties of the aluminum-based material. Detailed implementation modes

[0029] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] <Master alloy>

[0031] The present invention forms a zAl-xTiB 2 -yRE m O n master alloy, which enables rare earth oxides to better wrap on the surface of TiB 2 particles, improving the dispersibility of TiB 2 particles and the wettability between them and the matrix alloy, reducing the size of TiB 2 particles, and enhancing the strengthening effect of the master alloy on the aluminum-based material. The aluminum-based material described in the present invention includes aluminum alloys and metallic aluminum.

[0032] The master alloy of the present invention has the following composition:

[0033] zAl-xTiB 2 -yRE m O n .

[0034] TiB 2 represents titanium diboride. x represents the weight parts of TiB 2 . 1.0 ≤ x ≤ 20; preferably, 3.0 ≤ x ≤ 15. In some embodiments, 5.0 ≤ x ≤ 8. In some other embodiments, 9 ≤ x ≤ 12.

[0035] RE m O n represents rare earth oxide. The values of m and n are determined according to the valence state of the rare earth element. In some embodiments, m = 1, n = 2. In some other embodiments, m = 2, n = 3. RE m O n can be selected from La 2 O3 , CeO 2 , Nd 2 O 3 , Y 2 O 3 , Er 2 O 3 or more than one of; preferably, RE m O n is selected from La 2 O 3 , CeO 2 or Nd 2 O 3 or more than one of.

[0036] y represents the weight part of RE m O n . 0.1 ≤ y ≤ 10; preferably, 1 ≤ y ≤ 8; more preferably, 2 ≤ y ≤ 6.

[0037] Al represents aluminum element. z represents the weight part of Al. z = 100 - x - y. 80 ≤ z ≤ 95; preferably, 83 ≤ z ≤ 90; more preferably, 85 ≤ z ≤ 87.

[0038] The hydrogen content in the master alloy of the present invention is ≤ 0.15 mL / 100 g; preferably, the hydrogen content is ≤ 0.13 mL / 100 g; more preferably, the hydrogen content is ≤ 0.11 mL / 100 g.

[0039] According to an embodiment of the present invention, the master alloy has one of the following compositions:

[0040] 87Al - 10TiB 2 - 3La 2 O 3 ;

[0041] 85Al - 10TiB 2 - 5CeO 2 ;

[0042] 89Al - 6TiB 2 - 5Nd 2 O 3 ;

[0043] 85Al - 10TiB 2 - 5La 2 O 3 .

[0044] <Preparation method of master alloy>

[0045] The method for preparing the master alloy of the present invention comprises the following steps: (1) a step of forming a first precursor powder; (2) a step of forming a second precursor powder; and (3) a step of forming the master alloy.

[0046] Step of forming the first precursor powder

[0047] Disperse rare earth oxides in the melt formed by the first salt solvent, and then cool to obtain a first precursor; crush the first precursor to obtain the first precursor powder. The type and dosage of the rare earth oxides are determined according to the composition of the master alloy. The above steps can be carried out in a graphite crucible.

[0048] The first salt solvent includes potassium chloride, sodium chloride and cryolite. In some embodiments, the first salt solvent consists of potassium chloride, sodium chloride and cryolite.

[0049] In the first salt solvent, potassium chloride is 5-30 parts by weight; preferably 10-25 parts by weight; more preferably 15-20 parts by weight.

[0050] In the first salt solvent, sodium chloride is 20-50 parts by weight; preferably 20-40 parts by weight; more preferably 25-30 parts by weight.

[0051] In the first salt solvent, cryolite is 40-80 parts by weight; preferably 50-70 parts by weight; more preferably 60-65 parts by weight.

[0052] The mass ratio of the rare earth oxides to the first salt solvent is (0.01-0.5):1; preferably (0.1-0.4):1; more preferably (0.2-0.3):1.

[0053] According to an embodiment of the present invention, add the rare earth oxides to the melt formed by the first salt solvent, and stir to uniformly disperse the rare earth oxides in the melt formed by the first salt solvent to obtain a first mixture. This step can be carried out in a graphite crucible.

[0054] In some embodiments, it further includes a step of forming a melt: heating the first salt solvent to form a melt. This step can be carried out in a graphite crucible.

[0055] In some embodiments, pour the first mixture obtained by dispersing the rare earth oxides in the melt into a normal-temperature graphite crucible and cool to obtain the first precursor.

[0056] The particle size of the first precursor powder ≤ 3 cm.

[0057] The method of the present invention can uniformly disperse the rare earth oxides in the first salt solvent.

[0058] Step of forming the second precursor powder

[0059] Disperse titanium dioxide and boron oxide in the melt formed by the second salt solvent, and then cool to obtain a second precursor; crush the second precursor to obtain a second precursor powder. The dosages of titanium dioxide and boron oxide are determined according to the composition of the master alloy. The above steps can be carried out in a graphite crucible.

[0060] The second salt solvent includes potassium chloride, sodium chloride and cryolite. In some embodiments, the second salt solvent consists of potassium chloride, sodium chloride and cryolite.

[0061] In the second salt solvent, the potassium chloride is 5-30 parts by weight; preferably 10-25 parts by weight; more preferably 15-20 parts by weight.

[0062] In the second salt solvent, the sodium chloride is 20-50 parts by weight; preferably 20-40 parts by weight; more preferably 25-30 parts by weight.

[0063] In the second salt solvent, the cryolite is 40-80 parts by weight; preferably 50-70 parts by weight; more preferably 60-65 parts by weight.

[0064] The mass ratio of titanium dioxide to the second salt solvent is (0.01-0.5):1; preferably (0.1-0.4):1; more preferably (0.2-0.3):1.

[0065] According to an embodiment of the present invention, add titanium dioxide and boron oxide to the melt formed by the second salt solvent, and stir to make the titanium dioxide and boron oxide uniformly dispersed in the melt formed by the second salt solvent to obtain a second mixture. This step can be carried out in a graphite crucible.

[0066] In some embodiments, it further includes the step of forming a melt: heat the second salt solvent to form a melt. This step can be carried out in a graphite crucible.

[0067] In some embodiments, pour the second mixture obtained by dispersing titanium dioxide and boron oxide in the melt into a normal-temperature graphite crucible for cooling to obtain a second precursor.

[0068] The particle size of the second precursor powder ≤ 3 cm.

[0069] The method of the present invention can make titanium dioxide and boron oxide uniformly dispersed in the second salt solvent.

[0070] Step of forming the intermediate alloy

[0071] React the molten aluminum with the first precursor powder to obtain a first intermediate alloy liquid; react the first intermediate alloy liquid with the second precursor powder, and then remove the molten salt after the reaction to obtain a second intermediate alloy liquid; refine and degas the second intermediate alloy liquid, and then skim the slag to obtain an alloy liquid; shape the alloy liquid to obtain an intermediate alloy. In some embodiments, it further includes the step of melting metallic aluminum to form molten aluminum. The above steps can be carried out in a graphite crucible.

[0072] In the present invention, first, the molten aluminum reacts with the first precursor powder containing rare earth oxides through a redox reaction to displace the rare earth atoms in the rare earth oxides; then, the first intermediate alloy liquid reacts with the second precursor powder containing titanium dioxide and boron oxide. In this process, the rare earth atoms first react with titanium dioxide and boron oxide to generate free titanium atoms and boron atoms, and then the titanium atoms and boron atoms combine in-situ to form fine and dispersed titanium diboride phases, while the rare earth atoms in-situ form fine and dispersed rare earth oxides. The intermediate alloy formed in this way can play a better strengthening role than directly adding rare earth oxides and titanium diboride to the matrix material of the aluminum-based material.

[0073] The present invention reacts the molten aluminum with the first precursor powder to obtain a first intermediate alloy liquid.

[0074] The reaction temperature between the molten aluminum and the first precursor powder is 750 - 950 °C; preferably 800 - 900 °C; more preferably 850 - 870 °C.

[0075] According to an embodiment of the present invention, add the first precursor powder to the molten aluminum; under the stirring action, dissolve the first precursor powder in the molten aluminum; then keep warm to obtain a first intermediate alloy liquid.

[0076] The temperature of the molten aluminum can be 750 - 950 °C; preferably 800 - 900 °C; more preferably 850 - 870 °C.

[0077] The first precursor powder can be added to the molten aluminum in batches.

[0078] The graphite rotor of a degasser can be used to stir the first precursor powder and the molten aluminum.

[0079] The heat preservation time can be 10 - 60 min; preferably 20 - 50 min; more preferably 25 - 40 min.

[0080] This is beneficial to uniformly disperse the first precursor powder in the molten aluminum and enable the molten aluminum to fully react with the first precursor powder.

[0081] The present invention reacts the first intermediate alloy liquid with the second precursor powder, and then removes the molten salt after the reaction to obtain a second intermediate alloy liquid.

[0082] Specifically, the second precursor powder is added to the stirred first master alloy liquid; after the reaction between the second precursor powder and the first master alloy liquid is complete, the molten salt after the reaction is removed to obtain the second master alloy liquid.

[0083] A degassing machine graphite rotor can be used to stir the first master alloy liquid. This is beneficial for uniformly dispersing the second precursor powder in the first master alloy liquid, enabling the second precursor powder to fully react with the first master alloy liquid, and reducing the residual amount of molten salt in the obtained master alloy.

[0084] In the present invention, the second master alloy liquid is refined and degassed, and then slag is skimmed off to obtain the alloy liquid; the alloy liquid is formed to obtain the master alloy.

[0085] The second master alloy liquid can be refined and degassed using a degassing machine. Argon can be used to refine and degas the second master alloy liquid.

[0086] The temperature of the alloy liquid is 700 - 850 °C; preferably 720 - 800 °C; more preferably 730 - 750 °C.

[0087] After skimming off the slag, a cooling step can also be included to bring the alloy liquid to a suitable temperature.

[0088] Forming can be carried out using conventional methods in the art, such as casting, extrusion, continuous casting and rolling. The master alloy can be an alloy ingot, a rod-shaped alloy or a wire-shaped alloy.

[0089] <Use of the master alloy>

[0090] The master alloy of the present invention can effectively improve the mechanical strength of aluminum-based materials. Therefore, the present invention provides the use of the above master alloy in improving the mechanical strength of aluminum-based materials. The master alloy is as described above and will not be elaborated here.

[0091] Aluminum-based materials include metallic aluminum and aluminum alloys.

[0092] The aluminum alloy includes aluminum element. The aluminum alloy may also include one or more of silicon element, magnesium element, zinc element, copper element, manganese element, iron element.

[0093] The content of aluminum element can be 80 - 99.98 wt%; preferably 87 - 95.5 wt%; more preferably 90 - 93 wt%.

[0094] The content of silicon element can be 0.01 - 20 wt%; preferably 4.5 - 13 wt%; more preferably 6.5 - 7.5 wt%.

[0095] The content of magnesium element can be 0.01 - 11 wt%; preferably 0.1 - 5 wt%; more preferably 0.3 - 1 wt%.

[0096] The content of zinc element can be 0.0001 - 13 wt%; preferably 0.001 - 5 wt%; more preferably 0.01 - 0.1 wt%.

[0097] The content of copper element can be 0.00001 - 11 wt%; preferably 0.0001 - 1 wt%; more preferably 0.001 - 0.01 wt%.

[0098] The content of manganese element can be 0.0001 - 1.2 wt%; preferably 0.001 - 0.5 wt%; more preferably 0.01 - 0.1 wt%.

[0099] The content of iron element can be 0.001 - 1.2 wt%; preferably 0.01 - 0.8 wt%; more preferably 0.1 - 0.4 wt%.

[0100] <Preparation method of reinforced alloy>

[0101] The preparation method of the reinforced alloy of the present invention includes the following steps: forming a reinforced alloy liquid by using an intermediate alloy and an aluminum-containing substance; shaping the reinforced alloy liquid to obtain a reinforced alloy. The intermediate alloy is as described above and will not be elaborated here. In some embodiments, it further includes the step of preparing the intermediate alloy. The preparation method of the intermediate alloy is as described above and will not be elaborated here.

[0102] The present invention forms a reinforced alloy liquid by using an intermediate alloy and an aluminum-containing substance. The aluminum-containing substance can be selected from aluminum alloy, metallic aluminum or raw materials for forming aluminum alloy. The raw materials for forming aluminum alloy include but are not limited to metallic elements and metal alloys. The above steps can be carried out in a graphite crucible.

[0103] The aluminum-containing substance contains aluminum element. The aluminum-containing substance may further contain one or more of silicon element, magnesium element, zinc element, copper element, manganese element and iron element.

[0104] The content of aluminum element can be 80 - 100 wt%; preferably 80 - 99.98 wt%; more preferably 87 - 95.5 wt%; most preferably 90 - 93 wt%.

[0105] The content of silicon element can be 0.01 - 20 wt%; preferably 4.5 - 13 wt%; more preferably 6.5 - 7.5 wt%.

[0106] The content of magnesium element can be 0.01 - 11 wt%; preferably 0.1 - 5 wt%; more preferably 0.3 - 1 wt%.

[0107] The content of zinc element can be 0.0001 - 13 wt%; preferably 0.001 - 5 wt%; more preferably 0.01 - 0.1 wt%.

[0108] The content of copper element can be 0.00001-11 wt%; preferably 0.0001-1 wt%; more preferably 0.001-0.01 wt%.

[0109] The content of manganese element can be 0.0001-1.2 wt%; preferably 0.001-0.5 wt%; more preferably 0.01-0.1 wt%.

[0110] The content of iron element can be 0.001-1.2 wt%; preferably 0.01-0.8 wt%; more preferably 0.1-0.4 wt%.

[0111] The mass ratio of the master alloy to the aluminum-containing substance can be (0.01-50):1; preferably (0.05-20):1; more preferably (0.5-10):1; most preferably (3-7):1.

[0112] In some embodiments, the master alloy and the aluminum-containing substance are melted to form a molten alloy to be treated; the molten alloy to be treated is refined and degassed, and then the slag is skimmed to obtain a strengthened molten alloy.

[0113] According to an embodiment of the present invention, the aluminum-containing substance is an aluminum alloy or metallic aluminum. The aluminum-containing substance is formed into a molten metal, and the master alloy is added to the molten metal to obtain a molten alloy to be treated. The temperature of the molten metal is 680-850 °C; preferably 700-800 °C; more preferably 740-760 °C.

[0114] According to another embodiment of the present invention, the aluminum-containing substance is a raw material for forming an aluminum alloy. The master alloy is formed into a master alloy solution, and the raw material for forming the aluminum alloy is added to the master alloy solution to obtain a molten alloy to be treated. The temperature of the master alloy solution is 700-850 °C; preferably 730-800 °C; more preferably 750-780 °C.

[0115] Argon can be used to refine and degas the molten alloy to be treated.

[0116] A degassing machine with a graphite rotor can be used to refine and degas the molten alloy to be treated.

[0117] The argon pressure can be 0.1-0.5 MPa; preferably 0.2-0.4 MPa; more preferably 0.3-0.4 MPa.

[0118] The degassing time is 1-20 min; preferably 3-15 min; more preferably 5-10 min.

[0119] The rotation speed of the graphite rotor can be 50-300 r / min; preferably 100-250 r / min; more preferably 150-200 r / min.

[0120] The distance between the graphite rotor and the bottom of the graphite crucible is 1 - 7 cm; preferably 2 - 6 cm; more preferably 3 - 5 cm.

[0121] The temperature of the reinforced alloy liquid can be 650 - 800 °C; preferably 680 - 750 °C; more preferably 700 - 720 °C.

[0122] After the slag skimming step, cooling can also be carried out to make the reinforced alloy liquid reach a suitable temperature.

[0123] The present invention forms the reinforced alloy liquid to obtain the reinforced alloy. In some embodiments, the reinforced alloy liquid is cast into a mold to obtain the reinforced alloy.

[0124] The mold can be a steel mold. The temperature of the mold can be 200 - 300 °C; preferably 230 - 270 °C.

[0125] Example 1

[0126] According to the composition of the master alloy 87Al - 10TiB 2 -3La 2 O 3 Prepare the alloy raw materials. The aluminum element in the master alloy is provided by aluminum ingots. La in the master alloy is provided by lanthanum oxide 2 O 3 , and the dosage of the raw material lanthanum oxide is 1.35 times the theoretically required amount of the master alloy. The titanium element in the master alloy is provided by titanium dioxide, and the dosage of titanium dioxide is 1.15 times the theoretically required amount of the master alloy. The boron element in the master alloy is provided by boron oxide, and the dosage of boron oxide is 1.1 times the theoretically required amount of the master alloy.

[0127] Heat the first salt solvent in a graphite crucible to form a melt. Add lanthanum oxide to the melt formed by the first salt solvent, stir to make lanthanum oxide evenly dispersed in the melt formed by the first salt solvent to obtain a first mixture. Pour the first mixture into a normal temperature graphite crucible to cool, and obtain a first precursor. Crush the first precursor to obtain a first precursor powder with a particle size ≤ 3 cm. The first salt solvent consists of 15 parts by weight of potassium chloride, 25 parts by weight of sodium chloride, and 60 parts by weight of cryolite. The mass ratio of lanthanum oxide to the first salt solvent is 0.25.

[0128] Heat the second salt solvent in a graphite dry crucible to form a melt. Add titanium dioxide and boron oxide into the melt formed by the second salt solvent respectively, and stir to make titanium dioxide and boron oxide uniformly dispersed in the melt formed by the second salt solvent, obtaining a second mixture. Pour the second mixture into a normal-temperature graphite crucible to cool, obtaining a second precursor. Crush the second precursor to obtain a second precursor powder with a particle size ≤ 3 cm. The second salt solvent consists of 15 parts by weight of potassium chloride, 25 parts by weight of sodium chloride, and 60 parts by weight of cryolite. The mass ratio of titanium dioxide to the second salt solvent is 0.2.

[0129] Melt the aluminum ingot to obtain aluminum liquid at a temperature of 850 °C. Add the first precursor powder to the aluminum liquid in batches; under the stirring of the degassing graphite rotor, dissolve the first precursor powder in the aluminum liquid; then keep it warm for 25 min to obtain a first intermediate alloy liquid. Use the degassing graphite rotor to stir the first intermediate alloy liquid, and add the second precursor powder to the stirred first intermediate alloy liquid; after the reaction between the second precursor powder and the first intermediate alloy liquid is complete, ladle out the reacted molten salt to obtain a second intermediate alloy liquid. Refine and degas the second intermediate alloy liquid with argon, then skim the slag and cool down to obtain alloy liquid at a temperature of 730 °C. Cast the alloy liquid into ingots to obtain an intermediate alloy.

[0130] Example 2

[0131] Except that the composition of the intermediate alloy is 85Al - 10TiB 2 -5CeO 2 , CeO in the intermediate alloy is provided by cerium oxide 2 , except that the dosage of the raw material cerium oxide is 1.3 times the theoretically required amount of the intermediate alloy, the rest is the same as in Example 1.

[0132] Example 3

[0133] Except that the composition of the intermediate alloy is 89Al - 6TiB 2 -5Nd 2 O 3 , Nd in the intermediate alloy is provided by neodymium oxide 2 O 3 , except that the dosage of the raw material neodymium oxide is 1.35 times the theoretically required amount of the intermediate alloy, the rest is the same as in Example 1.

[0134] Example 4

[0135] Except that the composition of the intermediate alloy is 85Al - 10TiB 2 -5La 2 O 3 otherwise, the rest is the same as in Example 1.

[0136] Example 5

[0137] The aluminum alloy is melted in a graphite crucible to obtain a metal liquid at a temperature of 740 °C. The master alloy obtained in Example 1 is added to the metal liquid to obtain a alloy liquid to be treated. The mass ratio of the master alloy to the aluminum alloy is 1:1.

[0138] An in-line degasser with a graphite rotor is used, and argon is used to refine and degas the alloy liquid to be treated. Then, the slag is skimmed off and the temperature is lowered to obtain a strengthened alloy liquid at a temperature of 720 °C. The degassing time is 5 min, the argon pressure is 0.4 MPa, and the rotation speed of the graphite rotor is 150 r / min. The distance between the graphite rotor and the bottom of the graphite crucible is 4 cm.

[0139] The strengthened alloy liquid is cast into a steel mold preheated to 250 °C to obtain a strengthened alloy.

[0140] The composition of the aluminum alloy is shown in Table 1.

[0141] Table 1

[0142]

[0143] Example 6

[0144] Except that the master alloy is the master alloy obtained in Example 2, the rest is the same as in Example 5.

[0145] Example 7

[0146] The master alloy obtained in Example 3 is formed into a master alloy solution at 750 °C in a graphite crucible. Raw materials for forming the aluminum alloy are added to the master alloy solution, and then it is held at 750 °C for 15 min to obtain a alloy liquid to be treated. The raw materials for forming the aluminum alloy are composed of Al-20Si alloy, Mg metal, Zn metal, Cu metal, Al-Mn alloy and Al-Fe alloy. The specific content of each element in the raw materials for forming the aluminum alloy is shown in Table 2. The mass ratio of the master alloy to the raw materials for forming the aluminum alloy is 5:1.

[0147] An in-line degasser with a graphite rotor is used, and argon is used to refine and degas the alloy liquid to be treated. Then, the slag is skimmed off and the temperature is lowered to obtain a strengthened alloy liquid at a temperature of 720 °C. The degassing time is 5 min, the argon pressure is 0.4 MPa, and the rotation speed of the graphite rotor is 150 r / min. The distance between the graphite rotor and the bottom of the graphite crucible is 4 cm.

[0148] The strengthened alloy liquid is cast into a steel mold preheated to 250 °C to obtain a strengthened alloy.

[0149] Table 2

[0150]

[0151] Example 8

[0152] Except that the aluminum alloy is replaced with aluminum ingots and the master alloy is the master alloy obtained in Example 4, the rest is the same as in Example 5.

[0153] Comparative Example 1

[0154] Melt the same aluminum alloy as in Example 5 in a graphite crucible to obtain an aluminum alloy liquid at a temperature of 740 °C.

[0155] Use a degassing machine with a graphite rotor, and refine and degas the aluminum alloy liquid with argon, then skim the slag and cool down to obtain an alloy liquid at a temperature of 720 °C. The degassing time is 5 min, the argon pressure is 0.4 MPa, and the rotation speed of the graphite rotor is 150 r / min. The distance between the graphite rotor and the bottom of the graphite crucible is 4 cm.

[0156] Pour the alloy liquid into a steel mold preheated to 250 °C to obtain an alloy.

[0157] Comparative Example 2

[0158] Put the same aluminum ingots as in Example 8 into a graphite crucible and melt them to obtain aluminum liquid at a temperature of 740 °C.

[0159] Use a degassing machine with a graphite rotor, and refine and degas the aluminum liquid with argon, then skim the slag and cool down to obtain aluminum liquid at a temperature of 720 °C. The degassing time is 5 min, the argon pressure is 0.4 MPa, and the rotation speed of the graphite rotor is 150 r / min. The distance between the graphite rotor and the bottom of the graphite crucible is 4 cm.

[0160] Pour the aluminum liquid into a steel mold preheated to 250 °C to obtain pure aluminum.

[0161] Experimental Example

[0162] 1. Test the tensile strength, yield strength and elastic modulus of the metal by the following method: Use wire cutting and CNC lathe equipment to process tensile specimens on the ingot according to the regulations of GB / T 228-2010. The tensile specimens are subjected to tensile tests on a universal testing machine at a tensile rate of 0.5 mm / min. From the data obtained from the testing machine, the values of tensile strength, yield strength and elastic modulus can be calculated.

[0163] The results obtained are shown in Table 3.

[0164] Table 3

[0165]

[0166] 2. The hydrogen content of the aluminum ingots used in Example 1 and the master alloys in Examples 1-3 was measured using a hydrogen detector, and the results are shown in Table 4.

[0167] Table 4

[0168]

[0169] The present invention is not limited to the above embodiments. Without departing from the essence of the present invention, any variations, improvements, and substitutions that can be conceived by those skilled in the art fall within the scope of the present invention.

Claims

1. An intermediate alloy, characterized in that, the intermediate alloy has the following composition: zAl-xTiB 2 -yRE m O n ; Among them, RE represents a rare earth element, x represents the weight part of TiB 2 , y represents the weight part of RE m O n , z represents the weight part of Al, and m and n are determined according to the valence of RE; where 1.0 ≤ x ≤ 20, 0.1 ≤ y ≤ 10, z = 100 - x - y; Among them, RE m O n is selected from one or more of La 2 O 3 , CeO 2 , Nd 2 O 3 ; the hydrogen content in the intermediate alloy is ≤ 0.15 mL / 100 g.

2. The method for preparing the intermediate alloy according to claim 1, characterized in that, it comprises the following steps: (1) Dispersing rare earth oxide in the melt formed by the first salt solvent, and then cooling to obtain a first precursor; crushing the first precursor to obtain a first precursor powder; (2) Dispersing titanium dioxide and boron oxide in the melt formed by the second salt solvent, and then cooling to obtain a second precursor; crushing the second precursor to obtain a second precursor powder; (3) Reacting the aluminum liquid with the first precursor powder to obtain a first intermediate alloy liquid; reacting the first intermediate alloy liquid with the second precursor powder, then removing the molten salt after the reaction to obtain a second intermediate alloy liquid; refining and degassing the second intermediate alloy liquid, and then skimming the slag to obtain an alloy liquid; shaping the alloy liquid to obtain the intermediate alloy.

3. The preparation method according to claim 2, characterized in that, the first salt solvent includes potassium chloride, sodium chloride and cryolite; the second salt solvent includes potassium chloride, sodium chloride and cryolite.

4. The preparation method according to claim 3, characterized in that, in the first salt solvent, sodium chloride is 20 - 50 parts by weight, potassium chloride is 5 - 30 parts by weight, and cryolite is 40 - 80 parts by weight; in the second salt solvent, sodium chloride is 20 - 50 parts by weight, potassium chloride is 5 - 30 parts by weight, and cryolite is 40 - 80 parts by weight.

5. The preparation method according to claim 2, characterized in that, the particle size of the first precursor powder is ≤ 3 cm, and the particle size of the second precursor powder is ≤ 3 cm; the aluminum liquid reacts with the first precursor powder at 750 - 950 °C; the second intermediate alloy liquid is refined and degassed with argon; it is shaped by casting, and the temperature of the alloy liquid is 700 - 850 °C.

6. The use of the intermediate alloy according to claim 1 in enhancing the mechanical strength of aluminum-based materials.

7. A method for preparing a reinforcing alloy, characterized in that, it comprises the following steps: forming a reinforcing alloy liquid from the intermediate alloy according to claim 1 and an aluminum-containing substance; shaping the reinforcing alloy liquid to obtain a reinforcing alloy; wherein the aluminum-containing substance is selected from aluminum alloy or metallic aluminum.

8. The preparation method according to claim 7, characterized in that, it comprises the following steps: melting the intermediate alloy according to claim 1 and the aluminum-containing substance to form a to-be-treated alloy liquid; using argon to refine and degas the to-be-treated alloy liquid, and then skimming the slag to obtain a reinforcing alloy liquid.

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