CN111705232A

CN111705232A - Preparation method of aluminum-niobium-boron intermediate alloy for grain refinement, aluminum-niobium-boron intermediate alloy, aluminum-niobium-boron cast ingot and aluminum-niobium-boron alloy rope

Info

Publication number: CN111705232A
Application number: CN202010476260.1A
Authority: CN
Inventors: 路洪洲; 郭爱民; 徐金荣; 王文军; 郭俊杰; 崔天成
Original assignee: CITIC Metal Co Ltd
Current assignee: CITIC Metal Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2020-09-25

Abstract

The invention discloses a preparation method of an aluminum niobium boron intermediate alloy for grain refinement, which comprises the following steps: preparing industrial pure aluminum ingots, aluminum-niobium alloys and aluminum-boron alloys; melting an industrial pure aluminum ingot, and adding an aluminum-niobium alloy at the temperature of 1150-1250 ℃; controlling the obtained solution at 920-1250 ℃, and adding the aluminum-boron alloy; removing foam and slag from the obtained solution; and transferring the solution to a casting furnace, refining and degassing to prepare the aluminum-niobium-boron intermediate alloy. The method is simple and feasible, the content of impurity elements in the product is extremely low, and corrosive KBF in the casting process is avoided₄The use of salt and the use of aluminum niobium alloy instead of pure niobium improves the operability and reduces the cost. The Al-Nb-B intermediate alloy prepared by the method is used as a grain refiner, and has a uniform and fine structureThe alloy has the advantages of small degree, extremely low impurity content, convenient and efficient application, and capability of effectively avoiding metal burning loss, thereby ensuring the internal cleanliness of the alloy and having obvious effect of improving the crystal grains of the casting.

Description

Preparation method of aluminum-niobium-boron intermediate alloy for grain refinement, aluminum-niobium-boron intermediate alloy, aluminum-niobium-boron cast ingot and aluminum-niobium-boron alloy rope

Technical Field

The invention relates to the technical field of intermediate alloys, in particular to a preparation method of an aluminum-niobium-boron intermediate alloy for grain refinement, the aluminum-niobium-boron intermediate alloy, an aluminum-niobium-boron ingot and an aluminum-niobium-boron alloy rope.

Background

In the field of metal alloy, the alloy crystal grains are refined, so that the alloy properties including the strength and the plastic toughness of the material can be effectively improved, the hot cracking tendency is reduced, and the looseness is effectively inhibited, and the method is one of the most effective methods for improving the comprehensive mechanical properties of the alloy. Currently, the primary means of refining alloy grains is by adding "grain refiners" to the alloy, which are believed to be intermediate species that promote crystal optimization of the metal alloy.

With the continuous development of light weight of automobiles and the gradual implementation of national energy-saving and emission-reduction strategies, light alloys represented by aluminum and aluminum alloys are increasingly widely applied. The titanium-based grain refiner is typically an Al-Ti-B refiner, but the Ti element in the refiner reacts with Si in the Al-Si based casting alloy with high Si content to generate TiSi phase and TiSi phase₂Phase, in turn, weakens TiB₂The formation of particles weakens the refining effect and produces a poisoning effect, thereby limiting the application of the particles. The Brucella university and the like use pure niobium to prepare an aluminum-niobium-boron refined metal alloy, but the cost is higher; application No. 2017100434606 discloses an Al-Nb-B intermediate alloy refiner with a B content of 1-5%, however, the Al-Nb intermediate alloy of the refiner has obvious burning loss, more impurities, poor internal cleanliness and post-pair of B compoundsThe aluminum alloy product has obvious toxic action and still has defects on the improvement of the casting.

CN103370429B discloses a method for refining a metal alloy by adding sufficient niobium and boron to the aluminum alloy to be refined to form niobium diboride or Al₃Nb or both or (b) adding niobium diboride to the alloy. The niobium and boron are added in the form of pure niobium metal and pure boron, or niobium diboride, or Al₃Nb, niobium diboride in an amount of no more than 10% by weight of the alloy, at least 0.001% by weight, the master alloy having the formula Al-x% by weight Nb-y% by weight B, wherein x is in the range of 0.05 to 10 and y is in the range of 0.01 to 5.

CN105992833A discloses a high strength cast aluminium alloy for high pressure die casting containing other grain refining elements of Cr, Nb and Sc, which do not require how to add them to the alloy.

CN106498201A discloses an Al-Nb-Cr-B grain refiner and a preparation method thereof, wherein pure niobium, pure chromium, potassium fluoborate and industrial pure aluminum are applied to prepare the quaternary refiner, the content of niobium is 1.00-6.00%, and the content of niobium and boron is 0.5-1.0%. Because the simple substance form of Nb is not easy to be industrially prepared in large scale and is expensive, the method is not suitable for batch production, and the step of preparing the grain refining: heating a resistance furnace to 900-1200 ℃ for melting industrial pure aluminum, mixing and splitting pure niobium, pure chromium and potassium fluoborate by utilizing a graphite bell jar, pressing the mixture into an aluminum melt, introducing ultrasonic wave to vibrate the upper part of the melt, and casting the melt into an ingot-shaped Al-Nb-Cr-B grain refiner when the melt is naturally cooled to 700-720 ℃.

CN106591637A discloses a preparation method of an aluminum-niobium-boron intermediate alloy, which contains three main elements of aluminum, niobium and boron, and the mass percentages of the components are: 85.00% -95.00% of aluminum, 1.00% -10.00% of niobium and 1.00% -5.00% of boron; the raw materials comprise aluminum ingots, niobium metal, potassium fluoborate, hexachloroethane and the like, wherein the purity of the aluminum ingots is more than or equal to 99.9 percent; the Nb/B ratio is 3 and Nb/B is 5; placing pure aluminum in a resistance furnace for melting, heating to 800-1100 ℃, sequentially adding a certain mass of metal niobium or aluminum-niobium intermediate alloy and potassium fluoborate into the melted aluminum melt, fully stirring, placing in the resistance furnace for heat preservation, and refining and degassing by using hexachloroethane accounting for 2-3 wt% of the total mass. And (5) casting into ingots or preparing wires after the temperature is preserved for a certain time.

CN201380043494.5 discloses an Al-Nb-B master alloy for grain refinement, the method comprising providing an Al-B alloy and adding Nb in elemental form to form the Al-Nb-B master alloy. Since Nb in the elemental form is not easily industrially produced in a large scale and is expensive, it is not suitable for mass production.

CN105274413A discloses a Nb-Si-Ti-B-Al-Cr composite material and a preparation method thereof, wherein the method comprises the step of mixing silicon powder, titanium powder, boron powder, aluminum powder, chromium powder and niobium powder to prepare a 6-element composite material. 6-20% of Si, 3-25% of Ti, 1-10% of B, 3-15% of Al, 2-10% of Cr and the balance of Nb and inevitable impurities. The composite material is molybdenum alloy, is different from an industrial refiner, and uses elemental niobium metal as a raw material.

CN105506331A discloses a Mo-Si-B-Ti-Zr-Al-Nb composite material and a preparation method thereof, which restrict the component proportion and consist of the following substances in percentage by mole: 5-15% of Si, 5-15% of B, 10-30% of Ti, 3-7% of Zr, 2-8% of Al, 6-14% of Nb and the balance of Mo. The composite material is molybdenum alloy, is different from an industrial refiner, and uses elemental niobium metal as a raw material.

CN103700482 discloses a method for preparing a Fe-Si-B-Cu-Nb-Al-Ni low-cost nanocrystalline magnetic core for a high-frequency electronic transformer, wherein the Fe is an iron-based material, Fe is an impurity element of aluminum alloy and is different from an industrial refiner,

CN201810367998.7 discloses a preparation method and application of Ti-48Al-2Cr-2Nb alloy powder, wherein the method does not contain boron.

CN1428446 discloses a process for vacuum induction melting of Ti-Al-Nb-B alloy, which comprises using industrial pure Al, pure Nb and Al-B as raw materials. The atomic ratio of Ti to Al to Nb to B is 45: 46: 8: 1. Pure Nb is not suitable for industrial mass production.

CN201711274094.1 discloses an in-situ endogenous nanometer NbB₂The preparation method of the ceramic-aluminum composite material adopts boron powder as a raw materialAnd (5) feeding. The content of niobium powder is 8.11-32.45 wt.%; the content of the boron powder is 1.89-11.03 wt.%. Is a binary refiner.

CN201711273929.1 discloses a novel micro-nano NbB₂A granular aluminum alloy wire rod for welding, said method comprising (1) nano NbB₂Preparing an Al intermediate alloy; (2) containing nano NbB₂Preparing a granular aluminum alloy ingot; (3) homogenizing the cast ingot; (4) containing nano NbB₂Carrying out hot extrusion plastic forming on the granular aluminum alloy; (5) and (4) drawing and forming the aluminum alloy welding wire. The preparation process comprises the following steps: boron powder activation pretreatment, namely mixing, proportioning, compacting and molding aluminum powder, boron powder, niobium powder and copper powder.

CN201511030612.6 discloses a low-cooling-rate-sensitive high-nucleation-capacity AlNbBRE grain refiner for casting aluminum alloy and a preparation method thereof, and the refiner is characterized in that: the AlNbBRE grain refiner comprises Al-xNb-yB-zRE, wherein x is more than 0.01 and less than or equal to 6 wt%, y is more than 0.01 and less than or equal to 3 wt%, z is more than 0.01 and less than or equal to 1 wt%, and the balance is Al. The preparation process comprises the following steps: melting an aluminum block in a crucible of a resistance furnace, pressing weighed B raw materials and Nb raw materials into aluminum liquid by using a bell jar, adding Al-RE raw materials, adding a refining agent for refining, removing slag from the solution, and casting and molding.

CN201811078966.1 discloses a preparation method of an aluminum niobium boron alloy rod for grain refinement, wherein the method adopts potassium fluoborate as a B source material, and respectively weighs aluminum blocks, niobium powder and potassium fluoborate; proportioning: 2.5 to 3.5 wt.% of Nb, 0.2 to 0.5 wt.% of B, and the balance of Al. The process is as follows: heating and melting an aluminum block, preserving heat for at least 30 minutes at 800-900 ℃, adding the uniformly mixed niobium powder and potassium fluoborate in an Al foil wrapping mode, preserving heat for 60-120 minutes at 800-900 ℃, and stirring every 15 minutes.

And taking out the Al-Nb-B alloy ingot subjected to the preheating treatment, and carrying out hot extrusion on the Al-Nb-B alloy ingot to form the aluminum-niobium-boron alloy rod.

CN201810920166.3 discloses an Al-Nb-B intermediate alloy, a preparation method and an application thereof, wherein in the method, 2.0-3.5% of niobium (Nb), 0.1-0.99% of boron (B) and the balance of aluminum are used, 1) the mass ratio of the needed aluminum ingot, the Al-Nb alloy and potassium fluoborate is calculated according to the content of elements in a target product; 2) electric furnace smelting, deslagging and degassing 3) and continuous casting and rolling to obtain the Al-Nb-B intermediate alloy.

In summary, the method has the following disadvantages: firstly, the preparation of niobium-containing binary, ternary or multicomponent refiner by using simple substance niobium metal is not suitable for batch production and is expensive. Secondly, the borofluoride is adopted to prepare the binary, ternary or multicomponent refiner containing niobium and boron, and the borofluoride is added for reaction only by reducing the temperature from about 1100 ℃ to 800 ℃, so that the niobium is precipitated in aluminum liquid for a long time, and the yield of the niobium is low. Thirdly, a binary, ternary or multi-element refiner ingot or a continuous casting and rolling rod containing niobium and boron is directly added into the cast aluminum alloy to be refined, so that large-block refiner precipitation and Al3Nb and NbB2 agglomeration are caused, and the method is not suitable for modern casting technology. Fourthly, the ingot casting of binary, ternary or multi-element refiner containing niobium and boron is adopted for hot extrusion to form a rod, so that the agglomeration of Al3Nb and NbB2 can be relieved to a certain extent, and the agglomeration is superior to that of the ingot casting of the refiner but has the agglomeration problem. The related inventions of the related intermediate alloy do not show a process for wire pressing, winding and storing the product, and the use efficiency of preparing the metal alloy at the downstream is limited.

Therefore, how to provide a method for preparing an aluminum-niobium-boron intermediate alloy for grain refinement, an aluminum-niobium-boron intermediate alloy, an aluminum-niobium-boron ingot and an aluminum-niobium-boron alloy rope, which can avoid the above technical problems, becomes a technical problem which needs to be solved urgently by the technical personnel in the field.

Disclosure of Invention

The invention aims to provide a preparation method of an aluminum niobium boron intermediate alloy for grain refinement. In the method, an aluminum ingot is melted firstly, then an aluminum-niobium alloy is added, and then an aluminum-boron alloy is added, so that the use of corrosive KBF4 salt in a casting process is avoided, and the operability is improved by using the aluminum-niobium alloy instead of pure niobium.

The invention provides a preparation method of an aluminum niobium boron intermediate alloy for grain refinement, which comprises the following steps:

(a) preparing industrial pure aluminum ingots, aluminum-niobium alloys and aluminum-boron alloys;

(b) melting the industrial pure aluminum ingot, and adding the aluminum-niobium alloy into the industrial pure aluminum ingot at the temperature of 1150-1250 ℃;

(c) controlling the temperature of the solution obtained in the step (b) within the range of 920-1250 ℃, and adding the aluminum-boron alloy into the solution;

(d) defoaming and removing slag of the solution obtained in the step (c);

(e) and after the slag removal is finished, transferring the solution to a casting furnace, and refining and degassing to prepare the aluminum-niobium-boron intermediate alloy.

Preferably, the method further comprises the following steps after the step (e):

(f) and casting an aluminum-niobium-boron cast ingot, wherein the aluminum-niobium-boron cast ingot can be added into the cast aluminum alloy liquid as a grain refiner.

Preferably, the method further comprises the following steps after the step (f):

(g) and performing cold extrusion on the aluminum-niobium-boron cast ingot to prepare an aluminum-niobium-boron wire, and winding the aluminum-niobium-boron wire to form an aluminum-niobium-boron alloy rope, wherein the aluminum-niobium-boron alloy rope as a grain refiner can be added into the cast aluminum alloy liquid.

Preferably, in the step (a), the required amounts of the industrial pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy are prepared according to the mass percentage of each component in the target product aluminum-niobium-boron intermediate alloy, namely, the niobium content is 3-5%, the boron content is 0.3-0.5%, and the balance is aluminum, and the known aluminum-niobium content ratio in the aluminum-niobium alloy and the known aluminum-boron content ratio in the aluminum-boron alloy.

Preferably, in step (a), the purity of the commercial purity aluminum ingot is not less than 99.7% wt.

Preferably, in the step (b), the adding time of the aluminum-niobium alloy is less than or equal to 5min, and the stirring is continuously carried out during the adding process.

Preferably, in the step (c), the adding time of the aluminum boron alloy is less than or equal to 5min, and the stirring is continuously carried out during the adding process.

Preferably, the following operations are further included between the step (c) and the step (d):

and (c) adding an aluminum ingot into the solution obtained in the step (c) to adjust the content of each component in the target product of the aluminum-niobium-boron intermediate alloy.

Preferably, in the step (e), after the slag removal, the converter is transferred to a casting furnace, refining degassing is started when the temperature reaches 800 ℃, the refining time is 10-30 minutes, and the pressure of inert protective gas used for degassing is 0.1-0.3 MPa.

Preferably, in step (b), the commercially pure aluminum ingot is melted in an electromagnetic induction furnace.

Preferably, in the step (a), the required amount of the industrial pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy is calculated according to the mass percentage of each component in the target product of the aluminum-niobium-boron intermediate alloy, namely, the niobium content is 4%, the boron content is 0.3% -0.4%, and the balance is aluminum, and the known aluminum-niobium content ratio in the aluminum-niobium alloy and the known aluminum-boron content ratio in the aluminum-boron alloy.

Preferably, in the step (a), the required amounts of the process pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy are calculated according to the 'mass ratio of niobium to boron of 9-11: 1' in the target product.

Preferably, the desired aluminum niobium alloy has a niobium content of 50 to 70 wt%.

Preferably, the extrusion ratio of the cold extrusion is equal to or greater than 10.

Preferably, the method for winding the aluminum-niobium-boron wire to form the aluminum-niobium-boron alloy rope comprises the following steps:

4/6/8/10/12/14 aluminum niobium boron wires are wound to prepare the aluminum niobium boron alloy rope, wherein:

if 4/6/8 wires are wound by using a single-layer winding structure, the aluminum-niobium-boron wires are spirally wound clockwise during winding;

if 10/12/14 wires are wound by using a double-layer winding structure, the aluminum niobium boron wires are wound by corresponding to 4 inner layers and 6/8/10 outer layers of the aluminum niobium boron wires, the inner layers of the aluminum niobium boron wires are spirally wound clockwise, and the outer layers of the aluminum niobium boron wires are spirally wound anticlockwise.

The preparation method of the aluminum niobium boron intermediate alloy for grain refinement provided by the invention has the following technical effects:

the method comprises melting aluminum ingot, adding aluminum-niobium alloy at 1150-1250 deg.C, and adding aluminum-boron alloy at 920-1250 deg.C, with the advantages of simple process, low impurity content, and no corrosion in casting processSex KBF₄The use of salt and the use of aluminum niobium alloy instead of pure niobium improves the operability and reduces the cost. The aluminum-niobium-boron intermediate alloy prepared by the method is used as a grain refiner, has uniform structure, small fineness, extremely low impurity content, convenient and efficient application, and can effectively avoid metal burning loss, thereby ensuring the internal cleanliness of the alloy, reducing oxidation impurities and obviously improving the comprehensive mechanical property of later-stage castings; the service performance of the intermediate alloy is ensured; when the alloy is used as a grain refiner, the consumption is small, the use is convenient and efficient, the alloy is uniformly dispersed, and the improvement effect on casting grains is obvious.

Preferably, an aluminum niobium boron ingot of suitable gauge can be cast and added as a grain refiner to the cast aluminum alloy liquid.

Preferably, the aluminum niobium boron alloy rope can be prepared and added into the casting aluminum alloy liquid as a grain refiner, and under the action of the high-temperature casting aluminum alloy liquid, the winding structure of the aluminum niobium boron alloy rope is scattered due to internal stress, so that multi-point supply of aluminum niobium boron wires is formed, and the refining effect is better.

Preferably, the required quantity of the industrial pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy is calculated according to the mass percentage of each component in the target product aluminum-niobium-boron intermediate alloy, namely, the niobium content is 3-5%, the boron content is 0.3-0.5%, and the balance is aluminum, and the known aluminum-niobium content ratio in the aluminum-niobium alloy and the known aluminum-boron content ratio in the aluminum-boron alloy, so that the aluminum-niobium-boron intermediate alloy with the niobium content of 3-5%, the boron content of 0.3-0.5%, and the balance being aluminum can be finally prepared.

In addition, researches show that the excessive boride has obvious toxic action on aluminum alloy products in later period, the refining effect is not ideal when the boron content is less than 0.1%, the metal burning loss is aggravated when the boron content exceeds 0.99%, so that the cleanliness and the mechanical property of the alloy are influenced, and meanwhile, the aluminum alloy products in later period are poisoned when the boron content exceeds 0.99%; the applicant finds that the synergistic promotion of 3.0-5.0% of niobium and 0.3-0.5% of boron is most obvious, the refining capacity is improved, meanwhile, the poison to aluminum alloy products is inhibited, the metal burning loss is effectively avoided, the internal cleanliness of the alloy is ensured, the oxidation impurities are reduced, and meanwhile, the comprehensive mechanical property of later-stage castings is improved.

Preferably, the adding time of the aluminum niobium alloy and the aluminum boron alloy is limited not to exceed 5min, and compared with the prior art that the proper intermediate alloy can be formed only after the adding time is at least more than 20min, the method can form the proper intermediate alloy by adding the aluminum niobium alloy and the aluminum boron alloy within the limited time due to the unique steps of adding the aluminum niobium alloy and the aluminum boron alloy, and greatly improves the production efficiency.

Preferably, an aluminum ingot is added into the solution after the step (c), and the aluminum ingot can be used for adjusting the content of each component in the target product of the aluminum-niobium-boron intermediate alloy.

Preferably, in the step (a), the required amount of the industrial pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy is calculated according to the mass percentage of each component in the target product of the aluminum-niobium-boron intermediate alloy, namely, the niobium content is 4%, the boron content is 0.3% -0.4%, and the balance is aluminum, and the known aluminum-niobium content ratio in the aluminum-niobium alloy and the known aluminum-boron content ratio in the aluminum-boron alloy. After the aluminum niobium boron intermediate alloy with the content is added into the alloy solution, the grain refinement effect is good.

Preferably, the mass ratio of niobium to boron is limited to 9-11:1, and the proportioning enables the master alloy to have better grain refining effect.

Preferably, the rope with a single-layer winding structure or a double-layer winding structure can be manufactured and can be used in different working conditions.

The invention also provides an aluminum niobium boron intermediate alloy which is prepared by the method, so that the technical effects are the same.

The invention also provides an aluminum-niobium-boron intermediate alloy which comprises the components of niobium, boron and aluminum, wherein the mass percent of niobium is 3-5%, the mass percent of boron is 0.3-0.5%, the balance is aluminum, and the mass ratio of niobium to boron is 9-11: 1; the master alloy with limited content is used as a grain refiner, the refining effect is good, the synergistic promotion among the components is most obvious, the refining capacity is improved, the poison to aluminum alloy products is also inhibited, the metal burning loss is effectively avoided, the internal cleanliness of the alloy is ensured, the oxidation impurities are reduced, and the comprehensive mechanical property of later-stage castings is improved.

Preferably, the aluminum niobium boron intermediate alloy is in the shape of an ingot, and the cross-sectional diameter of the aluminum niobium boron ingot is 20mm-50 mm. The cast ingot-shaped aluminum alloy master alloy has the same technical effects.

Preferably, the aluminum-niobium-boron intermediate alloy is an aluminum-niobium-boron wire, the aluminum-niobium-boron wire is formed by adopting a cold extrusion mode, the extrusion ratio is more than or equal to 10, and the mode has the following effects: when the cold extrusion ratio reaches 10, internal stress is generated inside the aluminum-niobium-boron wire, and meanwhile, the cold extrusion can crush massive tissues and enable the tissues to be more compact and uniform, so that more dispersive Al can be generated₃Nb and NbB₂The particle is nucleated.

Preferably, the diameter of the aluminum niobium boron wire is 2-5 mm; this defined diameter has the following effect: adding the aluminum-niobium-boron wire into the casting aluminum alloy solution to be refined, wherein the aluminum-niobium-boron wire is required to be fully dispersed in the casting aluminum alloy solution to form more dispersed Al₃Nb and NbB₂Particle, avoid particle agglomeration problem. On the premise of adding aluminum-niobium-boron wires with certain weight percentage, the smaller the diameter of the aluminum-niobium-boron wires is, the Al is₃Nb and NbB₂The more dispersed the particles, the more dispersed the Al₃Nb and NbB₂Can effectively avoid particle agglomeration, and the dispersed particles are used as nucleation cores to ensure that the cast aluminum alloy crystal particles achieve the best refining effect.

Preferably, the diameter is 2 to 3 mm.

The invention also provides an aluminum niobium boron ingot which is prepared by the method, so the technical effects are the same as the above.

The invention also provides an aluminum-niobium-boron alloy rope which is prepared by the method, so that the technical effects are the same as those of the aluminum-niobium-boron alloy rope. And the diameter of the alloy rope is limited to be 4-9mm, and the following effects are achieved: aluminium niobium boron alloy rope winding arrangement takes place the thermal expansion deformation because the effect of casting aluminum alloy melt high temperature, single aluminium niobium boron filament thermal expansion deformation in the rope winding arrangement produces internal stress and then scatters, with the multiple spot supply that forms aluminium niobium boron filament, it is better to refine the effect, the diameter of rope excessively produces the melting and causes the problem that unmelted rope deposits the stove bottom slowly, the diameter undersize of rope, it is few to cause single aluminium niobium boron filament, the rope winding is too inseparable, be difficult for the filament to be heated and scatter, the multiple spot supply of influence refiner.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of one embodiment of the method for preparing an Al-Nb-B master alloy for grain refinement according to the present invention;

FIG. 2 is a diagram illustrating the effect of the aluminum-niobium-boron alloy rope as a grain refiner on refining aluminum alloy;

FIG. 3 is a diagram showing the effect of the aluminum niobium boron ingot provided by the invention as a grain refiner on refining aluminum alloy.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-3, fig. 1 is a flow chart of an embodiment of the method for preparing an aluminum niobium boron master alloy for grain refinement according to the present invention;

Referring to fig. 1, the present invention provides a method for preparing an aluminum niobium boron master alloy for grain refinement, comprising the following steps:

(b) melting an industrial pure aluminum ingot, and adding an aluminum-niobium alloy into the ingot at the temperature of 1150-1250 ℃;

(c) controlling the temperature of the solution obtained in the step (b) within the range of 920-1250 ℃, and adding an aluminum-boron alloy into the solution;

(d) defoaming and removing slag of the solution obtained in the step (c);

The method comprises melting aluminum ingot, adding aluminum-niobium alloy at 1150-1250 deg.C, and adding aluminum-boron alloy at 920-1250 deg.C, with the advantages of simple process, low impurity content, and no corrosion of KBF in casting process₄The use of salt and the use of aluminum niobium alloy instead of pure niobium improves the operability and reduces the cost. The aluminum-niobium-boron intermediate alloy prepared by the method is used as a grain refiner, has uniform structure, small fineness, extremely low impurity content, convenient and efficient application, and can effectively avoid metal burning loss, thereby ensuring the internal cleanliness of the alloy, reducing oxidation impurities and obviously improving the comprehensive mechanical property of later-stage castings; the service performance of the intermediate alloy is ensured; when the alloy is used as a grain refiner, the consumption is small, the use is convenient and efficient, the alloy is uniformly dispersed, and the improvement effect on casting grains is obvious (see attached figures 2 and 3).

As shown in fig. 1, the method further comprises the following steps after the step (e):

Thus, an aluminum niobium boron ingot with a suitable specification can be cast, and the aluminum niobium boron ingot can be added as a grain refiner into the cast aluminum alloy liquid, and the refining effect is shown in fig. 3.

Further, as shown in fig. 1, the step (f) is followed by the following steps:

The aluminum-niobium-boron alloy rope can be prepared and added into the cast aluminum alloy liquid as a grain refiner, and under the action of the high-temperature cast aluminum alloy liquid, the winding structure of the aluminum-niobium-boron alloy rope is scattered due to internal stress, so that the aluminum-niobium-boron wire is supplied in multiple points, and the refining effect is better. The effect of the refinement is shown in fig. 2.

In the present invention, in step (a), the required amounts of the industrial pure aluminum ingot, the aluminum-niobium alloy, and the aluminum-boron alloy may be prepared according to the mass percentages of the components in the target aluminum-niobium-boron intermediate alloy, that is, "niobium content 3% to 5%, boron content 0.3% to 0.5%, and balance aluminum", and "known aluminum-niobium content ratio in aluminum-niobium alloy, and known aluminum-boron content ratio in aluminum-boron alloy".

Thus, the aluminum-niobium-boron intermediate alloy with the niobium content of 3-5%, the boron content of 0.3-0.5% and the balance of aluminum can be finally prepared.

Further, the purity of the industrial pure aluminum ingot required is not less than 99.7% wt.

Further, the adding time of the aluminum-niobium alloy is less than or equal to 5min, and the stirring is continuously carried out in the adding process; the adding time of the aluminum boron alloy is less than or equal to 5min, and the stirring is continuously carried out in the adding process.

The method limits the adding time of the aluminum niobium alloy and the aluminum boron alloy to be not more than 5min, compared with the prior art that the adding time is at least more than 20min to ensure the formation of the proper intermediate alloy, the method can form the proper intermediate alloy by adding the aluminum niobium alloy and the aluminum boron alloy within the limited time due to the unique steps of adding the aluminum niobium alloy and the aluminum boron alloy, and greatly improves the production efficiency.

Wherein, the following operations are also included between the step (c) and the step (d):

Further, in the step (e), after the slag removal is finished, the converter is transferred to a casting furnace, refining degassing is started when the temperature reaches 800 ℃, the refining time is 10-30 minutes, and the pressure of inert protective gas adopted for degassing is 0.1-0.3 Mpa. The inert shielding gas used may be argon.

Furthermore, in step (b), an industrial pure aluminum ingot may be melted in an electromagnetic induction furnace. But is not limited thereto.

Further, in the step (a), the required amount of the industrial pure aluminum ingot, the aluminum-niobium alloy and the aluminum-boron alloy is calculated according to the mass percentage of each component in the target product of the aluminum-niobium-boron intermediate alloy, namely that the niobium content is 4%, the boron content is 0.3% -0.4%, and the balance is aluminum, and that the known aluminum-niobium content ratio in the aluminum-niobium alloy and the known aluminum-boron content ratio in the aluminum-boron alloy. After the aluminum niobium boron intermediate alloy with the content is added into the alloy solution, the grain refinement effect is good.

Meanwhile, the mass ratio of niobium to boron can be limited to 9-11:1, and the intermediate alloy has a good grain refining effect due to the proportion.

Further, the mass content of niobium in the required aluminum-niobium alloy is 50-70 wt%. The proportions of the components in the desired aluminium niobium alloy and aluminium boron alloy are known.

In the method, the extrusion ratio of the aluminum-niobium-boron wire formed by cold extrusion is more than or equal to 10.

In the method, the method for winding the aluminum-niobium-boron wire to form the aluminum-niobium-boron alloy rope comprises the following steps:

Therefore, the rope with a single-layer winding structure or a double-layer winding structure can be manufactured and can be used in different working conditions.

Specifically, the following examples are intended to prepare the target product aluminum niobium boron master alloy, which includes 3.5% niobium, 0.35% boron (B), and the balance pure aluminum, the aforementioned percentages being by mass.

The preparation method comprises the following steps:

1) liquid transferring: 500Kg of industrial pure aluminum liquid is transferred into an electromagnetic oven, and the temperature of the oven is raised to 1200 ℃.

2) The first reaction: stirring the mixture under opening, using a shovel to perform multiple times, slowly adding 40Kg of aluminum-niobium 60 alloy, and taking care that the feeding process is uniform, wherein the feeding time is 5 min;

3) adding aluminum boron alloy (AlB) into the furnace at 1050 + -20 deg.C₃)80kg, finishing the feeding within 5min and reacting.

4) Detecting and analyzing, and adding the balance of pure aluminum ingot according to the content of niobium to 3.5 percent of Nb and 0.35 percent of B.

5) After the reaction is finished, slag removal and refining degassing are started, and the argon pressure is 0.1-0.3 Mpa; (ii) a

6) Slightly adjusting the components, when the temperature to be cast is 710-730 ℃, the ingot with the length of 50mm, the height of 20mm and the weight of 650g is cast, and the total weight is about 500 Kg.

7) Taking the prepared intermediate alloy ingot containing 3.5 percent of niobium, and extruding an aluminum-niobium-boron wire by using a cold extruder, wherein the diameter of the aluminum-niobium-boron wire is 2mm, and the extrusion ratio lambda is 10.

8) And winding the aluminum-niobium-boron wire to prepare the aluminum-niobium-boron alloy rope, wherein the winding mode of the aluminum-niobium-boron rope is as follows: the alloy is made by sharing 14 medium-sized 2mm aluminum niobium boron wires, and the final diameter reaches about 9 mm. The product has an inner-layer structure and an outer-layer structure, and the number of the inner layers of the aluminum-niobium-boron ropes is 4, and the number of the outer layers of the aluminum-niobium-boron ropes is 10. The inner layer of aluminum-niobium-boron wires are spirally wound clockwise, the outer layer of aluminum-niobium-boron wires is spirally wound anticlockwise, and the preparation of the aluminum-niobium-boron rope is completed.

Further, the aluminum-niobium-boron alloy rope prepared in the example is added into the A356 aluminum alloy, and the A356 aluminum alloy is treated. And the microstructure was observed, and the particle distribution was as shown in FIG. 2. Therefore, the refining effect is good.

In addition, the ingot-shaped master alloy can also be added into the A356 aluminum alloy to finish the treatment of the A356 aluminum alloy. And the microstructure thereof was observed, and the particle distribution thereof was as shown in FIG. 3. The effect is also better, but compared with fig. 2, the addition of the aluminum niobium boron alloy rope is preferred.

Further, the aluminum niobium boron intermediate alloy is in an ingot shape, and the cross-sectional diameter of the aluminum niobium boron ingot is 20mm-50 mm. The cast ingot-shaped aluminum alloy master alloy has the same technical effects.

Further, an Al-Nb-B master alloy may also be presentThe aluminum-niobium-boron wire is formed by adopting a cold extrusion mode, the extrusion ratio is more than or equal to 10, and the mode has the following effects: when the cold extrusion ratio reaches 10, internal stress is generated inside the aluminum-niobium-boron wire, and meanwhile, the cold extrusion can crush massive tissues and enable the tissues to be more compact and uniform, so that more dispersive Al can be generated₃Nb and NbB₂The particle is nucleated. .

Wherein the diameter of the aluminum niobium boron wire is 2-5 mm; this defined diameter has the following effect: adding the aluminum-niobium-boron wire into the casting aluminum alloy solution to be refined, wherein the aluminum-niobium-boron wire is required to be fully dispersed in the casting aluminum alloy solution to form more dispersed Al₃Nb and NbB₂Particle, avoid particle agglomeration problem. On the premise of adding aluminum-niobium-boron wires with certain weight percentage, the smaller the diameter of the aluminum-niobium-boron wires is, the Al is₃Nb and NbB₂The more dispersed the particles, the more dispersed the Al₃Nb and NbB₂Can effectively avoid particle agglomeration, and the dispersed particles are used as nucleation cores to ensure that the cast aluminum alloy crystal particles achieve the best refining effect.

Preferably, the diameter is 2-3 mm.

The invention also provides an aluminum-niobium-boron alloy rope which is manufactured by the method or formed by winding the aluminum-niobium-boron wire. So the technical effect is the same. And the diameter of the alloy rope is limited to be 4-9mm, and the following effects are achieved: aluminium niobium boron alloy rope winding arrangement takes place the thermal expansion deformation because the effect of casting aluminum alloy melt high temperature, single aluminium niobium boron filament thermal expansion deformation in the rope winding arrangement produces internal stress and then scatters, with the multiple spot supply that forms aluminium niobium boron filament, it is better to refine the effect, the diameter of rope excessively produces the melting and causes the problem that unmelted rope deposits the stove bottom slowly, the diameter undersize of rope, it is few to cause single aluminium niobium boron filament, the rope winding is too inseparable, be difficult for the filament to be heated and scatter, the multiple spot supply of influence refiner.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the aluminum niobium boron intermediate alloy for grain refinement is characterized by comprising the following steps:

(d) defoaming and removing slag of the solution obtained in the step (c);

2. The method of preparing an al-nb-b master alloy for grain refinement as claimed in claim 1, further comprising the following steps after step (e):

3. The method of preparing an al-nb-b master alloy for grain refinement as claimed in claim 2, further comprising the step of, after step (f):

4. The method of producing an aluminum niobium boron intermediate alloy for grain refinement according to claim 1 or 2, characterized in that in step (a), the required amounts of the industrial pure aluminum ingot, the aluminum niobium alloy and the aluminum boron alloy are prepared according to the mass percentages of the components in the target product aluminum niobium boron intermediate alloy "niobium content is 3% to 5%, boron content is 0.3% to 0.5%, balance is aluminum" and "aluminum niobium content ratio known in aluminum niobium alloy, aluminum boron content ratio known in aluminum boron alloy".

5. The method for preparing an aluminum niobium boron master alloy for grain refinement according to claim 1 or 2, characterized in that in step (a), the purity of the industrial pure aluminum ingot is not less than 99.7% wt.

6. The method of claim 1 or 2, wherein the Al-Nb-B alloy is added in step (b) for a period of time less than or equal to 5min while stirring is continued.

7. The method of preparing an Al-Nb-B master alloy for grain refinement according to claim 1 or 2, wherein in the step (c), the Al-B alloy is added for less than or equal to 5min, and stirring is continued during the addition.

8. The method for preparing an aluminum niobium boron master alloy for grain refinement according to claim 1 or 2, characterized by further comprising the following operations between step (c) and step (d):

9. The method for preparing an Al-Nb-B master alloy for grain refinement according to claim 1 or 2, wherein in the step (e), refining degassing is started from a converter to a casting furnace after slag removal is finished at a temperature of 800 ℃, the refining time is 10-30 minutes, and the pressure of inert shielding gas used for degassing is 0.1-0.3 MPa.

10. The method of preparing an al-nb-b master alloy for grain refinement as claimed in claim 1 or 2, wherein in step (b), the industrial pure aluminum ingot is melted in an electromagnetic induction furnace.

11. The method of preparing an Al-Nb-B intermediate alloy for grain refinement according to claim 4, wherein in step (a), the required amounts of the industrial pure Al-ingot, Al-Nb alloy and Al-B alloy are calculated according to the mass percentages of the components of the target Al-Nb-B intermediate alloy, namely "Nb content is 4%, B content is 0.3-0.4%, and the balance is Al", and "known Al-Nb content ratio in Al-Nb alloy and known Al-B content ratio in Al-B alloy".

12. The method for preparing an Al-Nb-B master alloy for grain refinement according to claim 4, wherein in the step (a), the required amounts of the process pure Al ingot, the Al-Nb alloy and the Al-B alloy are calculated according to the "mass ratio of Nb to B of 9-11: 1" in the target product.

13. The method of producing an aluminum niobium boron master alloy for grain refinement as claimed in claim 1 or 2, wherein the aluminum niobium alloy is required to have a niobium content of 50 to 70% by mass.

14. The method for preparing an Al-Nb-B master alloy for grain refinement according to claim 3, wherein the extrusion ratio of the cold extrusion is not less than 10.

15. The method for preparing the Al-Nb-B intermediate alloy for grain refinement according to claim 3, wherein the method for winding the Al-Nb-B wire to form the Al-Nb-B alloy rope comprises the following steps:

16. An aluminium niobium boron master alloy characterised by being produced by a process as claimed in claim 1 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13.

17. The aluminum-niobium-boron intermediate alloy is characterized by comprising the components of niobium, boron and aluminum, wherein the mass percentage of niobium is 3-5%, the mass percentage of boron is 0.3-0.5%, the balance is aluminum, and the mass ratio of niobium to boron is 9-11: 1.

18. The al-nb-b master alloy according to claim 17, wherein the al-nb-b master alloy is in the form of an al-nb-b ingot having a cross-sectional diameter of 20mm to 50 mm.

19. The aluminum-niobium-boron intermediate alloy of claim 17, wherein the aluminum-niobium-boron intermediate alloy is in the form of aluminum-niobium-boron wires, the aluminum-niobium-boron wires are formed by cold extrusion, and the extrusion ratio of the cold extrusion is greater than or equal to 10.

20. The al-nb-b intermediate alloy as claimed in claim 19, wherein the al-nb-b wire has a diameter of 2-5 mm.

21. The al-nb-b intermediate alloy as claimed in claim 20, wherein the al-nb-b wire has a diameter of 2-3 mm.

22. An ingot of aluminium niobium boron, characterised in that it is produced by a process as defined in claim 2 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13.

23. The aluminum niobium boron ingot of claim 22, wherein the aluminum niobium boron ingot has a cross-sectional diameter of 20-50 mm.

24. An aluminum niobium boron alloy rope, characterized in that it is produced by the method of claim 3 or 14 or 15, and the diameter of the rope is 4-9 mm.

25. An aluminum niobium boron alloy rope, characterized in that the aluminum niobium boron alloy rope is formed by winding the aluminum niobium boron wire of claim 19, 20 or 21, and the diameter of the aluminum niobium boron alloy rope is 4-9 mm.