Aluminum-tungsten-titanium alloy and preparation method thereof

Abstract

The invention provides an aluminum-tungsten-titanium alloy and a preparation method thereof, and belongs to the technical field of alloy materials. Tungsten chloride, titanium oxide and coarse aluminum particles are firstly prepared into raw material bags and placed in a molten pool, then tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride mixed powder are placed between the raw material bags, after a magnesium rod is ignited, the tungsten trioxide, titanium oxide, aluminum particles and potassium chlorate are preferentially subjected to an aluminothermic reduction reaction to release a large amount of heat, and the aluminum particles and the calcium fluoride are subjected to heat treatment. And when the temperature reaches 1100-1200 DEG C, a reduction reaction occurs in the raw material bag, the reaction rate in the raw material bag is adjusted through the feeding mode of the raw material bag, meanwhile, the total heat of the aluminothermic reduction reaction is reduced, the alloy solidification speed is increased, and the segregation phenomenon caused by the density difference between metals is reduced. The result of the embodiment shows that in-ingot deviation of the tungsten element in the prepared aluminum-tungsten-titanium alloy is small, the uniformity of the aluminum-tungsten-titanium alloy is good, the impurity content is low, and the requirement of the tungsten-containing intermediate alloy for the high-temperature titanium alloy is met.

Description

Technical Field

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

[0002] Tungsten is an important additive element for high-temperature titanium alloys, and has the following functions: tungsten can enable high-temperature titanium alloys to maintain high strength and hardness in high-temperature environments; improve the mechanical properties and heat resistance of the alloy; enhance the alloy's plastic deformation ability at high temperatures; enhance the elastic modulus and porosity of titanium alloys, and improve the compressive strength and toughness of titanium alloys; tungsten can improve the high-temperature stability of titanium alloys, thereby increasing the service life of titanium alloys under high-temperature conditions; reduce the stress relaxation rate and creep deformation rate of titanium alloys at high temperatures, thereby giving titanium alloy materials better mechanical properties and high-temperature stability at high temperatures.

[0003] At present, tungsten sources for high-temperature titanium alloys are mostly added in the form of aluminum-tungsten-titanium alloys. However, during the smelting process, due to the inconsistency of the melting points of aluminum, tungsten, and titanium metal elements, adding various metal elements separately will cause the applied smelting current to fluctuate and be difficult to control, resulting in unstable smelting. The prepared titanium alloy ingots are prone to defects such as tungsten segregation and tungsten inclusions, making it difficult to obtain high-quality aluminum-tungsten-titanium alloys. For example, the relevant prior art discloses that by mixing the metal tungsten source with a flux, when the aluminum liquid temperature is 700-1300°C, the raw materials are added to the melt using a feeding device, and the electromagnetic induced eddy current effect is used to make the metal tungsten quickly melt in the low-temperature aluminum alloy liquid, and after homogenization treatment, it is cast into an ingot at 700-1300°C to obtain an aluminum-tungsten intermediate alloy with a mass percentage of tungsten of 1-10%. The aluminum-tungsten alloy prepared by this method has too low a content, and cannot be added to the high-temperature titanium alloy smelting process. For another example, the related prior art discloses that tungsten powder and aluminum powder are mixed in proportion, sintered into aluminum-tungsten alloy bars by spark plasma sintering, the aluminum-tungsten alloy bars are welded into an aluminum-tungsten alloy frame, and the top of the frame is placed in a medium-frequency furnace for casting and water-cooled copper crucible for standby use; the smelted aluminum-tungsten alloy liquid is cast into a water-cooled copper crucible equipped with an aluminum-tungsten alloy frame, and a highly uniform aluminum-tungsten alloy is obtained after cooling; this method of producing aluminum-tungsten alloy has low efficiency and high cost, and cannot be promoted on a large scale.

[0004] Therefore, how to prepare a high-quality aluminum-tungsten-titanium alloy with a simple and easy-to-implement method is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide an aluminum-tungsten-titanium alloy and a preparation method thereof. The method provided by the present invention is simple and can obtain high-quality aluminum-tungsten-titanium alloy.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing an aluminum-tungsten-titanium alloy, comprising the following steps:

[0008] (1) mixing tungsten chloride, titanium oxide and coarse aluminum particles and then performing alloy packaging to obtain a raw material package; the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles is (11-20): (1-5): (4-14);

[0009] (2) mixing tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride to obtain a mixed powder; the mass ratio of the tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride is (10-17): (2-5): (10-15): (1-4): (0.5-2.5);

[0010] (3) packing the raw material packages obtained in step (1) into the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages, wherein the number of the raw material packages is two or more; the ratio of the mass of tungsten chloride, titanium oxide and coarse aluminum particles in the raw material packages to the mass of the mixed powder is (14-16):(54-85);

[0011] (4) Using a magnesium rod to ignite the mixed powder in step (3), performing an aluminothermic reaction and then cooling to obtain an aluminum-tungsten-titanium alloy.

[0012] Preferably, the particle size of the coarse aluminum particles in step (1) is 1 to 8 mm.

[0013] Preferably, the shell made of the alloy in step (1) is a high-purity aluminum foil, and the thickness of the high-purity aluminum foil is 0.01 to 0.1 mm.

[0014] Preferably, the method for preparing the alloy package in step (1) comprises: wrapping a mixture obtained by mixing tungsten chloride, titanium oxide and coarse aluminum particles with high-purity aluminum foil, and then pressing the mixture to obtain a raw material package.

[0015] Preferably, the pressing pressure is 3 to 10 MPa, and the pressing time is 6 to 12 hours.

[0016] Preferably, in the step (2), the particle sizes of tungsten trioxide and titanium oxide are independently ≤30 μm; and the particle size of fine aluminum particles is ≤0.8 mm.

[0017] Preferably, the number of raw material packages in step (3) is 5 to 10 groups.

[0018] Preferably, the total reaction average unit charge heat effect of the thermite reaction in step (4) is ≤750 kcal / kg.

[0019] Preferably, in step (4), cooling after the thermite reaction also includes sequentially performing high-pressure sandblasting, crushing, screening and finishing.

[0020] The present invention also provides an aluminum-tungsten-titanium alloy prepared by the preparation method described in the above technical scheme, comprising the following elements in percentage by mass: 45-65% tungsten, 6-14% titanium, ≤0.15% iron, ≤0.15% silicon, ≤0.4% carbon, ≤0.2% oxygen, ≤0.1% nitrogen and the remainder aluminum.

[0021] The invention provides a method for preparing an aluminum-tungsten-titanium alloy, comprising the following steps: mixing tungsten chloride, titanium oxide and coarse aluminum particles and then performing alloy packaging to obtain a raw material package; the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles is (11-20): (1-5): (4-14); mixing tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride to obtain a mixed powder; the mass ratio of the tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride is (10 ~17):(2~5):(10~15):(1~4):(0.5~2.5); pack the raw materials into the molten pool, fill the mixed powder between the raw materials packs, the number of the raw materials packs is more than two groups; the ratio of the mass of tungsten chloride, titanium oxide and coarse aluminum particles in the raw materials packs to the mass of the mixed powder is (14~46):(54~85); ignite the mixed powder with a magnesium rod, perform an aluminothermic reaction and then cool to obtain an aluminum-tungsten-titanium alloy. The present invention prepares raw materials packs of tungsten chloride, titanium oxide and coarse aluminum particles and places them in the molten pool, and then places a mixed powder of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride between the raw materials packs. When ignited with a magnesium rod, the following reaction occurs:

[0022] WO3+2Al→W+Al2O3 (1)

[0023] 3TiO2+4Al→ 3Ti+Al2O3 (2)

[0024] KClO3+2Al→KCl+Al2O3 (3)

[0025] WCl6+2Al→W+2AlCl3 (4)

[0026] The ignition temperature of the magnesium bar is between 480 and 510°C. After ignition, tungsten trioxide, titanium oxide, aluminum particles, and potassium chlorate preferentially undergo aluminothermic reduction reactions (1), (2), and (3), releasing a large amount of heat. When the temperature reaches 1100 to 1200°C, the materials in the raw material package undergo reduction reactions (2) and (4). Therefore, after the reaction occurs, the outside of the raw material package preferentially reacts, and the released heat is absorbed by the raw material package. Aluminothermic reduction reaction occurs in the raw material package, but the aluminothermic reduction reaction in the raw material package releases less heat. Therefore, the aluminothermic reaction is adjusted by the raw material package to adjust the reaction rate in the raw material package, while reducing the total heat of the aluminothermic reduction reaction, accelerating the solidification rate of the alloy, and reducing the segregation phenomenon caused by the density difference between metals. The results of the embodiments show that the aluminum-tungsten-titanium alloy prepared by the present invention has the following contents: tungsten 45-65%, titanium 6-14%, aluminum, iron ≤0.15%, silicon ≤0.15%, carbon ≤0.4%, oxygen ≤0.2%, nitrogen ≤0.1% and the remainder aluminum. It has high tungsten content, small deviation of tungsten element ingot, good uniformity of aluminum-tungsten-titanium alloy and low impurity content, which meets the demand for tungsten-containing intermediate alloys for high-temperature titanium alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the arrangement of the raw material package and the mixed powder in the molten pool in an embodiment of the present invention;

[0028] Among them: 1 is thermite reaction graphite molten pool, 2 is mixed powder, and 3 is the raw material package. DETAILED DESCRIPTION

[0029] The present invention provides a method for preparing an aluminum-tungsten-titanium alloy, comprising the following steps:

[0030] (1) mixing tungsten chloride, titanium oxide and coarse aluminum particles and then performing alloy packaging to obtain a raw material package; the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles is (11-20): (1-5): (4-14);

[0031] (2) mixing tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride to obtain a mixed powder; the mass ratio of the tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride is (10-17): (2-5): (10-15): (1-4): (0.5-2.5);

[0032] (3) packing the raw material packages obtained in step (1) into the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages, wherein the number of the raw material packages is two or more; the mass ratio of tungsten chloride, titanium oxide and coarse aluminum particles in the raw material packages to the mass ratio of the mixed powder is (14-46):(54-85);

[0033] (4) Using a magnesium rod to ignite the mixed powder in step (3), performing an aluminothermic reaction and then cooling to obtain an aluminum-tungsten-titanium alloy.

[0034] The invention mixes tungsten chloride, titanium oxide and coarse aluminum particles and then performs alloy packaging to obtain a raw material package.

[0035] In the present invention, the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles is (11-20): (1-5): (4-14), preferably (15-19.5): (1-3): (6-12). In an embodiment of the present invention, the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles can be 19.5: 2.3: 8.3, 19.5: 2.7: 7.5 or 19: 1.5: 6.3. The present invention controls the usage of the three within the above range, which can make full use of the aluminothermic reaction to adjust the reaction rate in the raw material package, while reducing the total heat of the aluminothermic reduction reaction, accelerating the solidification rate of the alloy, and reducing the segregation phenomenon caused by the density difference between metals.

[0036] In the present invention, the particle size of the coarse aluminum particles is preferably 1 to 8 mm, more preferably 2 to 4 mm. The present invention controls the particle size of the coarse aluminum particles within the above range, which is more conducive to controlling the appropriate reaction rate in the raw material package.

[0037] In the present invention, the purity of the coarse aluminum particles is preferably ≥99.95wt%. The present invention controls the purity of the coarse aluminum particles within the above range, which is more conducive to obtaining high-quality aluminum-tungsten-titanium alloy.

[0038] In the present invention, the particle size of the titanium oxide is preferably ≤30 μm, more preferably 10 to 25 μm. The particle size of the titanium oxide is controlled within the above range, which is more conducive to uniform mixing with tungsten chloride and coarse aluminum particles.

[0039] The present invention has no particular limitation on the method of mixing the tungsten chloride, titanium oxide and coarse aluminum particles, as long as the components can be mixed evenly.

[0040] In the present invention, the shell of the alloy package is preferably high-purity aluminum foil, and the thickness of the high-purity aluminum foil is preferably 0.01-0.1 mm, more preferably 0.05-0.1 mm. The present invention uses high-purity aluminum foil as the shell of the alloy package, which can introduce less impurities when preparing the aluminum-tungsten-titanium alloy.

[0041] The present invention has no special limitation on the size of the raw material packages. The size of the raw material packages can be adjusted according to the amount of tungsten chloride, titanium oxide and coarse aluminum particles used to make the required number of raw material packages.

[0042] In the present invention, the alloy bag making method preferably comprises: wrapping a mixture obtained by mixing tungsten chloride, titanium oxide and coarse aluminum particles with high-purity aluminum foil, and then pressing the mixture to obtain a raw material bag.

[0043] The present invention has no special limitation on the wrapping method, as long as the tungsten chloride, titanium oxide and coarse aluminum particles can be fully wrapped by the high-purity aluminum foil.

[0044] In the present invention, the pressing pressure is preferably 3-10 MPa, more preferably 4-6 MPa; the pressing time is preferably 6-12 hours, more preferably 8-12 hours. The present invention can discharge the gas in the raw material package through pressing, making the mixture of tungsten chloride, titanium oxide and coarse aluminum particles more dense.

[0045] The invention mixes tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride to obtain mixed powder.

[0046] In the present invention, the mass ratio of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride is (10-17): (2-5): (10-15): (1-4): (0.5-2.5), preferably (11-17): (2-5): (10-15): (1-4): (0.5-2.5). In an embodiment of the present invention, the mass ratio of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride can be 13.25: 2.65: 10.5: 4: 2.5, 10.1: 2.4: 10.9: 2: 1.2 or 11.9: 2.85: 10.9: 2.1: 1.25. The present invention controls the mass ratio of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride within the above range, which can promote the aluminothermic reaction of each component and release a large amount of heat.

[0047] In the present invention, the particle sizes of the tungsten trioxide, titanium oxide and fine aluminum particles are independently preferably ≤0.8 mm, more preferably ≤0.4 mm. The present invention controls the particle size of each component within the above range, which is more conducive to full contact of each component and promotes a more complete thermite reaction.

[0048] The present invention has no particular limitation on the method of mixing the tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride, as long as the components can be mixed uniformly.

[0049] After obtaining the raw material package and the mixed powder, the present invention packs the raw material package into an aluminothermic reaction molten pool, and fills the mixed powder between the raw material packages. The present invention has no special limitation on the device for the aluminothermic reaction, and any conventional aluminothermic reaction device can be used. In an embodiment of the present invention, the aluminothermic reaction molten pool can be an aluminothermic reaction graphite molten pool.

[0050] In the present invention, the number of the raw material packages is more than two groups, preferably 5 to 10 groups, and more preferably 8 to 10 groups. The present invention controls the number of raw material packages within the above range, which is more conducive to uniform distribution in the molten pool and allows the mixed powder to be filled between the raw material packages, thereby allowing the heat of the aluminum heat reaction of the mixed powder to be fully absorbed by the raw material packages.

[0051] The present invention has no particular limitation on the method of placing the raw material packages into the molten pool, as long as the raw material packages can be evenly distributed in the molten pool. In an embodiment of the present invention, the schematic diagram of the arrangement of the raw material packages and the mixed powder in the molten pool is preferably as follows: Figure 1 shown.

[0052] In the present invention, the mixed powder is preferably compacted after being filled between the raw material bags. The present invention can make the powder obtained by mixing tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride more tightly combined by compaction, and exhaust the air therein.

[0053] In the present invention, the mass ratio of tungsten chloride, titanium oxide and coarse aluminum particles in the raw material package to the mass ratio of the mixed powder is (14-46): (54-85), preferably (30-40): (60-80). The present invention controls the mass ratio of tungsten chloride, titanium oxide and coarse aluminum particles in the raw material package to the mass ratio of the mixed powder within the above range, which can control the total reaction average unit charge heat effect of the thermal reaction to ≤750kcal / kg, thereby meeting the heat required for the thermite reaction.

[0054] After the mixed powder is filled between the raw material packages, the present invention uses a magnesium bar to ignite the mixed powder, performs an aluminum thermal reaction, and then cools the mixed powder to obtain an aluminum-tungsten-titanium alloy.

[0055] The present invention has no special limitation on the amount of the magnesium strip, as long as it can ignite the mixed powder.

[0056] In the present invention, the thermite reaction is an exothermic reaction. After the magnesium bar is ignited, the thermite reaction can be spontaneously carried out by utilizing the heat release, so that tungsten trioxide, titanium oxide, aluminum particles, and potassium chlorate preferentially undergo thermite reduction reaction to release a large amount of heat. When the temperature reaches 1100-1200°C, the materials in the raw material package undergo a reduction reaction.

[0057] The present invention has no special limitation on the cooling method, and the product after the aluminothermic reaction can be cooled to room temperature. The present invention obtains an aluminum-tungsten-titanium alloy ingot by cooling. In an embodiment of the present invention, the thickness of the aluminum-tungsten-titanium alloy ingot can be 8 to 18 cm. In an embodiment of the present invention, the cooling method can be furnace cooling.

[0058] The present invention preferably further includes high-pressure sandblasting, crushing, screening and finishing selection after cooling after the thermite reaction. The present invention can further surface treat and process the aluminum-tungsten-titanium alloy ingot into an aluminum-tungsten-titanium alloy of the required size through high-pressure sandblasting, crushing, screening and finishing selection. The present invention does not specifically limit the operation method of the high-pressure sandblasting, crushing, screening and finishing selection, and the conventional high-pressure sandblasting, crushing, screening and finishing selection operation method can be used. In an embodiment of the present invention, the high-pressure sandblasting is preferably performed with aluminum particles for surface treatment, and the particle size of the aluminum particles can be 1 to 2 mm.

[0059] The method provided by the present invention first prepares a raw material package of tungsten chloride, titanium oxide and coarse aluminum particles and places it in a molten pool, then places a mixed powder of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride between the raw material packages and compacts them, and after a magnesium bar is used to ignite a reaction, a reaction occurs first outside the raw material package, and heat is absorbed by the raw material package, and an aluminothermic reduction reaction occurs inside the raw material package. The aluminothermic reaction is adjusted through the raw material package to adjust the reaction rate inside the raw material package, and at the same time, the total heat of the aluminothermic reduction reaction is reduced, the solidification speed of the alloy is accelerated, and the segregation phenomenon caused by the density difference between metals is reduced.

[0060] The present invention also provides an aluminum-tungsten-titanium alloy prepared by the preparation method described in the above technical scheme, characterized in that it includes the following elements in percentage by mass: 45-65% tungsten, 6-14% titanium, ≤0.15% iron, ≤0.15% silicon, ≤0.4% carbon, ≤0.2% oxygen, ≤0.1% nitrogen and the remainder aluminum.

[0061] Since the preparation method of the present invention can adjust the reaction rate in the raw material package by the aluminum thermal reaction through the raw material package, and at the same time reduce the total heat of the aluminum thermal reduction reaction, accelerate the alloy solidification speed, and reduce the segregation phenomenon caused by the density difference between metals, the obtained aluminum tungsten titanium alloy has a higher tungsten content, the deviation of the tungsten element in the aluminum tungsten titanium alloy in the ingot is small, the aluminum tungsten titanium alloy has good uniformity, and the impurity content is small, so that high-quality aluminum tungsten titanium alloy is obtained.

[0062] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Example 1

[0064] A method for preparing an aluminum-tungsten-titanium alloy, comprising the following steps:

[0065] (1) 19.5 kg of tungsten chloride, 2.3 kg of titanium oxide and 8.3 kg of coarse aluminum particles (particle size 2-4 mm) were mixed uniformly and divided into 8 groups, and then respectively loaded into high-purity aluminum foil with a thickness of 0.05 mm, and pressed at 4 MPa for 8 hours to obtain 8 groups of raw material packages;

[0066] (2) 26.5 kg of tungsten trioxide, 5.3 kg of titanium oxide, 21 kg of fine aluminum particles (particle size ≤ 0.4 mm), 8 kg of potassium chlorate and 5 kg of calcium fluoride were mixed uniformly to obtain a mixed powder;

[0067] (3) placing the eight groups of raw material packages obtained in step (1) evenly in the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages and compacting them. At this time, the unit charge heat effect is 620 kcal / kg;

[0068] (4) The mixed powder in step (3) is ignited using a magnesium rod, subjected to an aluminum thermal reaction and then cooled to obtain 58.2 kg of an aluminum-tungsten-titanium alloy ingot with a thickness of 12 cm. The aluminum-tungsten-titanium alloy ingot is sandblasted, crushed, screened, and finely selected using a high-pressure sandblasting machine to obtain 50.5 kg of an aluminum-tungsten-titanium alloy finished product. The test results are shown in Table 1.

[0069] Table 1 Analysis of sampling results of aluminum tungsten titanium alloy prepared in Example 1

[0070]

[0071]

[0072] It can be seen from Table 1 that the aluminum-tungsten-titanium alloy prepared in this embodiment has good uniformity, the deviation of the tungsten element in the ingot is only 0.85wt%, and the content of impurity elements is low, which meets the demand for tungsten-containing master alloys for high-temperature titanium alloys.

[0073] Example 2

[0074] A method for preparing an aluminum-tungsten-titanium alloy, which is different from Example 1 in that:

[0075] (1) 19.5 kg of tungsten chloride, 2.7 kg of titanium oxide and 7.5 kg of crude aluminum particles were mixed evenly and divided into 7 groups, and then respectively loaded into high-purity aluminum foil with a thickness of 0.05 mm, and pressed at 5 MPa for 8 hours to obtain 7 groups of raw material packages;

[0076] (2) 20.2 kg of tungsten trioxide, 4.8 kg of titanium oxide, 21.8 kg of fine aluminum particles, 4 kg of potassium chlorate and 2.4 kg of calcium fluoride were mixed evenly;

[0077] (3) placing the seven groups of raw material packages obtained in step (1) evenly in the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages and compacting them. At this time, the unit charge heat effect is 634 kcal / kg;

[0078] (4) As in Example 1, 49.8 kg of aluminum-tungsten-titanium alloy product was obtained. The test results are shown in Table 2.

[0079] Table 2 Analysis of sampling results of aluminum tungsten titanium alloy prepared in Example 2

[0080]

[0081] It can be seen from Table 2 that the aluminum-tungsten-titanium alloy prepared in this embodiment has good uniformity, the deviation of the tungsten element in the ingot is only 0.43wt%, and the content of impurity elements is low, which meets the demand for tungsten-containing master alloys for high-temperature titanium alloys.

[0082] Example 3

[0083] A method for preparing an aluminum-tungsten-titanium alloy, which is different from Example 1 in that:

[0084] (1) 19 kg of tungsten chloride, 1.5 kg of titanium oxide and 6.3 kg of crude aluminum particles were mixed evenly and divided into 8 groups, and then respectively loaded into high-purity aluminum foil with a thickness of 0.05 mm, and pressed at 6 MPa for 8 hours to obtain 8 groups of raw material packages;

[0085] (2) 23.8 kg of tungsten trioxide, 5.7 kg of titanium oxide, 21.8 kg of fine aluminum particles, 4.2 kg of potassium chlorate and 2.5 kg of calcium fluoride were mixed uniformly to obtain a mixed powder;

[0086] (3) placing the eight groups of raw material packages obtained in step (1) evenly in the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages and compacting them. At this time, the unit charge heat effect is 657 kcal / kg;

[0087] (4) As in Example 1, 50.1 kg of aluminum-tungsten-titanium alloy product was obtained, and the test results are shown in Table 3.

[0088] Table 3 Analysis of sampling results of aluminum tungsten titanium alloy prepared in Example 3

[0089]

[0090] It can be seen from Table 3 that the aluminum-tungsten-titanium alloy prepared in this embodiment has good uniformity, the deviation of the tungsten element in the ingot is only 0.73wt%, and the content of impurity elements is low, which meets the demand for tungsten-containing master alloys for high-temperature titanium alloys.

[0091] It can be seen from the above results that the method provided by the present invention is simple to operate, and the tungsten element in the prepared aluminum-tungsten-titanium alloy has a small deviation in the ingot, good uniformity, and low impurity element content, and can obtain high-quality aluminum-tungsten-titanium alloy. This is because the present invention controls the preparation method, first prepares a raw material package of tungsten chloride, titanium oxide and coarse aluminum particles and places it in the molten pool, and then places a mixed powder of tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride between the raw material packages. After igniting with a magnesium bar, tungsten trioxide, titanium oxide, aluminum particles and potassium chlorate preferentially undergo aluminothermic reduction reaction to release a large amount of heat. When the temperature reaches 1100-1200°C, a reduction reaction occurs in the raw material package. The reaction rate in the raw material package is adjusted by the feeding method of the raw material package, and the total heat of the aluminothermic reduction reaction is reduced at the same time, the solidification speed of the alloy is accelerated, and the segregation phenomenon caused by the density difference between metals is reduced, thereby improving the quality of the aluminum-tungsten-titanium alloy.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing an aluminum-tungsten-titanium alloy, comprising the following steps: (1) mixing tungsten chloride, titanium oxide and coarse aluminum particles and then performing alloy packaging to obtain a raw material package; the mass ratio of the tungsten chloride, titanium oxide and coarse aluminum particles is (11-20): (1-5): (4-14); (2) mixing tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride to obtain a mixed powder; the mass ratio of the tungsten trioxide, titanium oxide, fine aluminum particles, potassium chlorate and calcium fluoride is (10-17): (2-5): (10-15): (1-4): (0.5-2.5); (3) packing the raw material packages obtained in step (1) into the molten pool, and filling the mixed powder obtained in step (2) between the raw material packages, wherein the number of the raw material packages is two or more; the mass ratio of tungsten chloride, titanium oxide and coarse aluminum particles in the raw material packages to the mass ratio of the mixed powder is (14-46):(54-85); (4) using a magnesium rod to ignite the mixed powder in step (3), performing an aluminothermic reaction, and then cooling to obtain an aluminum-tungsten-titanium alloy; There is no chronological order between step (1) and step (2).

2. The method for preparing the aluminum-tungsten-titanium alloy according to claim 1, characterized in that: The particle size of the coarse aluminum particles in step (1) is 1 to 8 mm.

3. The method for preparing the aluminum-tungsten-titanium alloy according to claim 1, characterized in that: In the step (1), the outer shell of the alloy package is a high-purity aluminum foil, and the thickness of the high-purity aluminum foil is 0.01-0.1 mm.

4. The method for preparing the aluminum-tungsten-titanium alloy according to claim 3, characterized in that: The method for preparing the alloy package in step (1) comprises: wrapping a mixture obtained by mixing tungsten chloride, titanium oxide and coarse aluminum particles with high-purity aluminum foil, and then pressing the mixture to obtain a raw material package.

5. The method for preparing aluminum-tungsten-titanium alloy according to claim 4, characterized in that: The pressing pressure is 3-10 MPa, and the pressing time is 6-12 hours.

6. The method for preparing aluminum-tungsten-titanium alloy according to claim 1, characterized in that: In the step (2), the particle sizes of tungsten trioxide and titanium oxide are independently ≤30 μm; and the particle size of fine aluminum particles is ≤0.8 mm.

7. The method for preparing aluminum-tungsten-titanium alloy according to claim 1, characterized in that: The number of raw material packages in step (3) is 5 to 10 groups.

8. The method for preparing aluminum-tungsten-titanium alloy according to claim 1, characterized in that: The total average unit charge heat effect of the thermite reaction in step (4) is ≤750 kcal / kg.

9. The method for preparing aluminum-tungsten-titanium alloy according to claim 1, characterized in that: The step (4) further includes the following steps of sequentially performing high pressure sandblasting, crushing, screening and finishing after cooling after the thermite reaction.

10. The aluminum-tungsten-titanium alloy prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The invention comprises the following elements in percentage by mass: tungsten 45-65%, titanium 6-14%, iron ≤0.15%, silicon ≤0.15%, carbon ≤0.4%, oxygen ≤0.2%, nitrogen ≤0.1% and the balance aluminum.

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