CN113122743A

CN113122743A - Al-V-B intermediate alloy and preparation method and application thereof

Info

Publication number: CN113122743A
Application number: CN202110443686.1A
Authority: CN
Inventors: 何立子; 王鑫; 王新宇; 刘宏亮; 高思睿
Original assignee: Northeastern University China
Current assignee: Northeastern University China
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2021-07-16
Anticipated expiration: 2041-04-23
Also published as: CN113122743B

Abstract

An Al-V-B master alloy and a preparation method and application thereof belong to the technical field of metal materials. The chemical elements of the alloy are composed of, by mass percentage, V: 2-3%, B: 1-2%, and the balance is Al ; Using pure Al, AlV ₅ bulk and KBF ₄ powder as raw materials to prepare Al‑V‑B master alloy. The preparation method of the Al-V-B master alloy of the present invention can make the distribution of V in the melt very uniform, and the V element can form second-phase particles such as Al ₁₀ V and VB ₂ , which help aluminum to generate heterogeneous nucleation and achieve fine-grained nucleation. The purpose of grain refinement is to set a reasonable content of V and B in the master alloy, so as to achieve the best grain refinement effect of aluminum or aluminum alloy.

Description

Al-V-B intermediate alloy and preparation method and application thereof

Technical Field

The invention belongs to the technical field of metal materials, and particularly relates to an Al-V-B intermediate alloy, and a preparation method and application thereof.

Background

As a light metal material, the aluminum alloy is widely applied to industries such as military industry, aerospace, automobiles, buildings, electronics and the like due to the characteristics of light weight, high strength, good plastic toughness, excellent cold processing performance and the like. With the development of industry, the requirements on the structure and the performance of aluminum and aluminum alloy obtained by subsequent deep processing are more strict, and the key point for controlling the structure and the performance is to obtain a fine and uniform cast-state grain structure. In industrial production, adding grain refiner into aluminum melt is one of the most economic and effective means.

At present, the aluminum alloy refiner mainly takes Al-Ti-B series as main materials and is mainly produced by adopting a villiaumite method, and the specific process is to mix KBF with a certain proportion₄And K₂TiF₆And adding the aluminum melt after uniform mixing, fully reacting, and casting and molding. At present, the production conditions and the technical level in China are relatively lagged, and the Al-Ti-B grain refiner made in China has the defects of low purity of the product, high loss of B element and TiAl₃、TiB₂The quantity is small, the agglomeration phenomenon is obvious and the like, the effect of the refiner can not meet the requirement of high-end aluminum materials, and the Al-Ti-B grain refiner in China still needs to be imported in large quantity. Therefore, it is necessary to develop a new high-quality grain refiner for aluminum alloys. Wherein, CN110157935A discloses an Al-V-B refiner for casting aluminum-silicon alloy, a preparation method and application thereof, the chemical element composition and the mass percentage are that aluminum is 80.0-95.8%, vanadium is 2.1-10.0%, boron is 2.1-10.0%, KBF is adopted₄The Al block and the V powder are smelted at the temperature of 750-850 ℃; however, the content of B in the method is higher than 2 percent, when a large amount of salt is added, the melt viscosity is overhigh, the salt melt mixture is seriously adhered and settled by using a simple smelting method, the prepared intermediate alloy has uneven components, the effect is uneven after alloy refining is carried out, and the higher use requirement of a grain refiner cannot be met.

Disclosure of Invention

Aiming at the technical problem, the invention provides an Al-V-B intermediate alloy, a preparation method and application thereof, and Al is formed by utilizing V element₁₀V and VB₂The second phase particles help aluminum to generate heterogeneous nucleation to achieve the purpose of grain refinement, so as to achieve the best aluminum/aluminum alloy grain refinement effect. The specific technical scheme is as follows:

an Al-V-B intermediate alloy comprises the following chemical elements in percentage by mass: 2-3%, B: 1-2% and the balance of Al;

the Al-V-B master alloy comprises: Al-2V-1B master alloy, Al-2V-2B master alloy, Al-3V-1B master alloy, and Al-3V-2B master alloy;

a preparation method of an Al-V-B intermediate alloy comprises the following steps:

step 1: weighing AlV according to the mass ratio of the Al-V-B intermediate alloy₅Block and KBF₄Powder, then adding AlV₅Block and KBF₄Wrapping the powder with aluminum foil, mixing, heating to 140 +/-5 ℃, drying for 2-3 h, and removing water;

step 2: placing the crucible in a heating furnace, preheating to 320 +/-10 ℃, then placing pure aluminum in the crucible, and heating until the pure aluminum is completely melted to form an aluminum melt; then wrapping with AlV₅Block and KBF₄Immersing the aluminum foil of the powder into the aluminum melt, and stirring the aluminum foil and the aluminum melt until the aluminum foil and the aluminum melt are uniformly mixed after all the aluminum foil is melted to form a mixed melt; at the moment, the components in the mixed melt are as follows by mass percent V: 2-3%, B: 1-2% and the balance of Al;

and step 3: heating the mixed melt to 810 +/-10 ℃, then preserving heat for 1-1.5 h, heating to 850 +/-10 ℃ after heat preservation, and continuing preserving heat for 30-40 min, wherein stirring is carried out once every 10-15 min during the period so as to ensure uniform melting; after the temperature is reduced to 800 +/-10 ℃, the temperature is preserved for 30-40 min, and the mixture is stirred once every 10-15 min during the period to reduce particle agglomeration and sedimentation and prevent B from being in gaseous BF₃Form loss;

and 4, step 4: and deslagging after heat preservation is finished, and casting into a copper water-cooled mold to prepare the Al-V-B intermediate alloy.

In said step 1, KBF₄The particle size of the powder is 85-100 mu m;

in the step 2, the purity of the pure aluminum is more than or equal to 99.9 percent;

the stirring rod is used for stirring, the stirring rod is made of titanium, and the surface of the stirring rod is coated with the boron nitride coating;

the application of the Al-V-B intermediate alloy is applied to grain refinement of aluminum or aluminum alloy;

the application method of the Al-V-B intermediate alloy comprises the following steps:

step 1: putting aluminum or aluminum alloy into a crucible and heating to melt to form a melt;

step 2: adding the Al-V-B intermediate alloy into the melt, stirring the melt until the Al-V-B intermediate alloy is molten, and uniformly mixing all the materials to form a uniform mixed melt;

and step 3: heating the mixed melt to 720 +/-5 ℃, preserving the heat for 10-15 min, and then casting into an ingot;

in the step 2, the addition amount of the Al-V-B intermediate alloy accounts for 0.1-0.2% of the total mass of the mixed melt according to the mass of V;

in the step 3, the average grain diameter of the cast ingot is 0.202-1.147 mm.

Compared with the prior art, the Al-V-B intermediate alloy and the preparation method and the application thereof have the beneficial effects that:

firstly, the invention controls the B element to be 1-2%, and excessive KBF addition is not caused₄The salt powder causes sedimentation and wall adhesion, which is beneficial to the smooth proceeding of the subsequent deslagging process; meanwhile, the utilization rate of the B element is improved, the pollution of the impurities of the adhesive to the intermediate alloy is reduced, and the quality uniformity of the intermediate alloy is improved.

Secondly, the crucible is placed in a heating furnace to be preheated to 320 +/-10 ℃, so that the subsequent Al melting time is shortened, and the efficiency is improved; the invention utilizes the aluminum foil pair AlV₅And KBF₄Wrapping to prevent oxidation of V and to enable V to be uniformly melted into Al melt, keeping the temperature at 850 ℃ for 30min to better melt V in the melt, and keeping the temperature at 800 ℃ for 30min to reduce BF to the maximum extent₃Loss of B in gaseous form; comprehensively improves the utilization rate of B, ensures that V is uniformly distributed in the melt, and achieves the purpose of refining grains by heterogeneous nucleation of the formed second phase particles.

The Al-V-B intermediate alloy has uniform texture and low impurity content generated by sedimentation or adhesion, and has uniform refining effect when being used for preparing aluminum or aluminum alloy and high quality of prepared products.

In conclusion, the Al-V-B master alloy of the present invention is preparedThe preparation method can make V distribute in the melt very uniformly, and the V element can form Al₁₀V and VB₂The second phase particles help aluminum to generate heterogeneous nucleation to achieve the purpose of grain refinement, and the reasonable content of V and B in the intermediate alloy is set, so that the best aluminum or aluminum alloy grain refinement effect is achieved.

Drawings

FIG. 1 is an XRD pattern of an Al-2V-2B master alloy of example 2 of the present invention;

FIG. 2 is an as-cast microstructure of an ingot of example 1 of the present invention after being anodically coated;

FIG. 3 is an as-cast microstructure of a comparative example ingot of example 1 of the present invention after being subjected to anodic coating;

FIG. 4 is an as-cast microstructure of an ingot of example 2 of the present invention after being anodically coated;

FIG. 5 is an as-cast microstructure of an ingot of example 3 of the present invention after being anodically coated;

FIG. 6 is an as-cast microstructure of an ingot of example 4 of the present invention after anodic coating;

FIG. 7 is an as-cast microstructure of an ingot of example 5 of the present invention after anodic coating;

FIG. 8 is an as-cast microstructure of a comparative example ingot of example 5 of the present invention after being subjected to anodic coating;

FIG. 9 is an as-cast microstructure of an ingot of example 6 of the present invention after being anodically coated;

FIG. 10 is an as-cast microstructure of an ingot of example 7 of the present invention after anodic coating;

FIG. 11 is an as-cast microstructure of an ingot of example 8 of the present invention after anodic coating;

FIG. 12 is an as-cast microstructure of an ingot of example 9 of the present invention after anodic coating;

FIG. 13 is an as-cast microstructure of a comparative example ingot of example 9 of the present invention after anodic coating;

FIG. 14 is an as-cast microstructure of an ingot of example 10 of the present invention after anodic coating;

FIG. 15 is an as-cast microstructure of an ingot of example 11 of the present invention after anodic coating;

FIG. 16 is an as-cast microstructure of an ingot of example 12 of the present invention after anodic coating;

Detailed Description

The invention will be further described with reference to specific embodiments and figures 1 to 16, but the invention is not limited to these embodiments.

Example 1

An Al-V-B intermediate alloy comprises the following chemical elements in percentage by mass: 2%, B: 1% and the balance of Al; the Al-V-B intermediate alloy is Al-2V-1B intermediate alloy;

step 1: weighing AlV according to the mass ratio of the Al-V-B intermediate alloy₅Block and KBF₄Powder, then adding AlV₅Block and KBF₄Wrapping the powder with aluminum foil, mixing, heating to 140 deg.C, and oven drying for 2 hr to remove water;

step 2: placing the crucible in a heating furnace, preheating to 320 ℃, then placing pure aluminum in the crucible, and heating until the pure aluminum is completely melted to form an aluminum melt; then wrapping with AlV₅Block and KBF₄Immersing the aluminum foil of the powder into the aluminum melt, and stirring the aluminum foil and the aluminum melt until the aluminum foil and the aluminum melt are uniformly mixed after all the aluminum foil is melted to form a mixed melt; at the moment, the components in the mixed melt are as follows by mass percent V: 2%, B: 1% and the balance of Al;

and step 3: heating the mixed melt to 810 ℃, then preserving heat for 1h, heating to 850 ℃ after heat preservation, and continuing preserving heat for 30min, wherein stirring is carried out once every 10min during the period so as to ensure uniform melting; cooling to 800 deg.C, maintaining the temperature for 30min, and stirring every 10min to reduce particle agglomeration and sedimentation and prevent gaseous BF of B₃Form loss;

and 4, step 4: and deslagging after heat preservation is finished, and then casting into a copper water-cooled mold to prepare the Al-2V-1B intermediate alloy.

In said step 1, KBF₄The particle size of the powder is 85-100 mu m;

step 1: putting pure aluminum into a crucible and heating to melt to form a melt;

step 2: adding the Al-2V-1B intermediate alloy into the melt, stirring the melt until the Al-2V-1B intermediate alloy is molten, and uniformly mixing all the materials to form a uniform mixed melt;

and step 3: heating the mixed melt to 720 ℃, preserving heat for 13min, and then casting into a cast ingot;

in the step 2, the adding amount of the Al-2V-1B intermediate alloy accounts for 0.18 percent of the total mass of the mixed melt according to the mass of V;

in the step 3, after the ingot is subjected to anodic coating, the average grain size of the ingot is 0.846mm, as shown in fig. 2.

In the present example, a comparative test was performed using pure aluminum without adding a master alloy to prepare an ingot, and the average grain size of the pure aluminum ingot was observed to be 3.167mm after the ingot of the comparative example was subjected to anodic coating, as shown in fig. 3.

Example 2

An Al-V-B intermediate alloy comprises the following chemical elements in percentage by mass: 2%, B: 2% and the balance of Al; the Al-V-B intermediate alloy is Al-2V-2B intermediate alloy;

step 1: weighing AlV according to the mass ratio of the Al-V-B intermediate alloy₅Block and KBF₄Powder, then adding AlV₅Block and KBF₄Wrapping the powder with aluminum foil, mixing, heating to 145 deg.C, oven drying for 2.5 hr to remove water;

step 2: preheating the crucible to 330 ℃ in a heating furnace, then placing pure aluminum in the crucible, and heating until the pure aluminum is completely melted to form an aluminum melt; then wrapping with AlV₅Block and KBF₄Immersing the aluminum foil of the powder into the aluminum melt, and stirring the aluminum foil and the aluminum melt until the aluminum foil and the aluminum melt are uniformly mixed after all the aluminum foil is melted to form a mixed melt; at the moment, the components in the mixed melt are as follows by mass percent V: 2%, B: 2% and the balance of Al;

and step 3: heating the mixed melt to 820 ℃, preserving heat for 1.2h, heating to 860 ℃ after heat preservation, and continuously preserving heat for 35min, wherein stirring is carried out once every 12min in the period so as to ensure uniform melting; maintaining the temperature for 35min after the temperature is reduced to 790 deg.C, and stirring once every 12min to reduce particle agglomeration and sedimentation and prevent gaseous BF of B₃Form loss;

and 4, step 4: and deslagging after heat preservation is finished, and then casting into a copper water-cooled mold to prepare the Al-2V-2B intermediate alloy, wherein an XRD (X-ray diffraction) pattern is shown in figure 1.

In said step 1, KBF₄The particle size of the powder is 85-100 mu m;

step 2: adding the Al-2V-2B intermediate alloy into the melt, stirring the melt until the Al-2V-2B intermediate alloy is molten, and uniformly mixing all the materials to form a uniform mixed melt;

and step 3: heating the mixed melt to 725 ℃, preserving heat for 12min, and then casting into a cast ingot;

in the step 2, the adding amount of the Al-2V-2B intermediate alloy accounts for 0.1 percent of the total mass of the mixed melt according to the mass of V;

in the step 3, after the ingot is subjected to anodic coating, the average grain size of the ingot is 1.122mm, as shown in fig. 4.

Example 3

An Al-V-B intermediate alloy comprises the following chemical elements in percentage by mass: 3%, B: 1% and the balance of Al; the Al-V-B intermediate alloy is Al-3V-1B intermediate alloy;

step 1: weighing AlV according to the mass ratio of the Al-V-B intermediate alloy₅Block and KBF₄Powder, then adding AlV₅Block and KBF₄Wrapping the powder with aluminum foil, mixing, heating to 135 deg.C, and oven drying for 3 hr to remove water;

step 2: placing the crucible in a heating furnace to preheat to 310 ℃, then placing pure aluminum in the crucible, and heating until the pure aluminum is completely melted to form an aluminum melt; then wrapping with AlV₅Block and KBF₄Immersing the aluminum foil of the powder into the aluminum melt, and stirring the aluminum foil and the aluminum melt until the aluminum foil and the aluminum melt are uniformly mixed after all the aluminum foil is melted to form a mixed melt; at the moment, the components in the mixed melt are as follows by mass percent V: 3%, B: 1% and the balance of Al;

and step 3: heating the mixed melt to 800 ℃, then preserving heat for 1.1h, heating to 840 ℃ after heat preservation, and continuing to preserve heat for 40min, wherein stirring is carried out once every 15min during the period, so as to ensure uniform melting; maintaining the temperature for 30min after the temperature is reduced to 790 deg.C, stirring every 10min to reduce particle agglomeration and sedimentation, and preventing gaseous BF of B₃Form loss;

and 4, step 4: and deslagging after heat preservation is finished, and then casting into a copper water-cooled mold to prepare the Al-3V-1B intermediate alloy.

In said step 1, KBF₄The particle size of the powder is 85-100 mu m;

step 2: adding Al-3V-1B intermediate alloy into the melt, stirring the melt until the Al-3V-1B intermediate alloy is molten, and uniformly mixing all the materials to form uniform mixed melt;

and step 3: heating the mixed melt to 715 ℃, preserving heat for 12min, and then casting into a cast ingot;

in the step 2, the addition amount of the Al-3V-1B intermediate alloy accounts for 0.1 percent of the total mass of the mixed melt according to the mass of V;

in the step 3, the average grain diameter of the cast ingot is 0.468mm as shown in fig. 5 after the cast ingot is subjected to anodic coating.

Example 4

An Al-V-B intermediate alloy comprises the following chemical elements in percentage by mass: 3%, B: 2% and the balance of Al; the Al-V-B intermediate alloy is Al-3V-2B intermediate alloy;

step 1: weighing AlV according to the mass ratio of the Al-V-B intermediate alloy₅Block and KBF₄Powder, then adding AlV₅Block and KBF₄Wrapping the powder with aluminum foil, mixing, heating to 142 deg.C, oven drying for 2.6 hr to remove water;

step 2: placing the crucible in a heating furnace to preheat to 325 ℃, then placing pure aluminum in the crucible, and heating until the pure aluminum is completely melted to form an aluminum melt; then wrapping with AlV₅Block and KBF₄Immersing the aluminum foil of the powder into the aluminum melt, and stirring the aluminum foil and the aluminum melt until the aluminum foil and the aluminum melt are uniformly mixed after all the aluminum foil is melted to form a mixed melt; at the moment, the components in the mixed melt are as follows by mass percent V: 3%, B: 2% and the balance of Al;

and step 3: heating the mixed melt to 815 ℃, preserving heat for 1.1h, heating to 845 ℃ after heat preservation, and continuously preserving heat for 40min, wherein stirring is carried out once every 15min during the period so as to ensure uniform melting; maintaining the temperature at 795 deg.C for 35min while stirring every 12min to reduce particle agglomeration and sedimentation and prevent gaseous BF of B₃Form loss;

and 4, step 4: and deslagging after heat preservation is finished, and casting into a copper water-cooled mold to prepare the Al-3V-2B intermediate alloy.

In said step 1, KBF₄The particle size of the powder is 85-100 mu m;

step 2: adding Al-3V-2B intermediate alloy into the melt, stirring the melt until the Al-3V-2B intermediate alloy is molten, and uniformly mixing all the materials to form uniform mixed melt;

and step 3: heating the mixed melt to 725 ℃, preserving heat for 15min, and then casting into a cast ingot;

in the step 2, the addition amount of the Al-3V-2B intermediate alloy accounts for 0.1 percent of the total mass of the mixed melt according to the mass of V;

in the step 3, after the ingot is subjected to anodic coating, the average grain size of the ingot is 1.034mm, as shown in fig. 6.

Example 5

An Al-V-B master alloy and a method for preparing the same as in example 1.

step 1: putting the Al-10Si alloy into a crucible and heating to melt to form a melt;

in the step 3, the average grain size of the cast ingot is 0.216mm as shown in fig. 7 after the cast ingot is subjected to anodic coating.

In the present example, an ingot was prepared from an Al-10Si alloy without adding an intermediate alloy, and a comparative example ingot was subjected to anodic coating, and the average grain size of the ingot was observed to be 1.575mm, as shown in fig. 8.

Example 6

An Al-V-B master alloy and a method for preparing the same as in example 2.

in the step 3, the average grain size of the cast ingot is 0.214mm as shown in fig. 9 after the cast ingot is subjected to anodic coating.

Example 7

An Al-V-B master alloy and a method for preparing the same as in example 3.

in the step 2, the addition amount of the Al-3V-1B intermediate alloy accounts for 0.15 percent of the total mass of the mixed melt according to the mass of V;

in the step 3, the average grain size of the cast ingot is 0.285mm after anode coating observation, as shown in fig. 10.

Example 8

An Al-V-B master alloy and a method for preparing the same as in example 4.

in the step 3, the average grain size of the ingot is 0.202mm as shown in fig. 11, which is observed after the ingot is subjected to anodic coating.

Example 9

An Al-V-B master alloy and a method for preparing the same as in example 1.

step 1: putting Al-0.9Mg-0.6Si alloy into a crucible and heating to melt to form a melt;

in the step 3, the average grain size of the cast ingot is 0.647mm as shown in fig. 12 after the cast ingot is subjected to anodic coating.

In the present example, an ingot was prepared from an Al-0.9Mg-0.6Si alloy without adding an intermediate alloy, and a comparative example ingot was subjected to anodic coating, and the average grain size of the ingot was observed to be 2.235mm, as shown in fig. 13.

Example 10

An Al-V-B master alloy and a method for preparing the same as in example 2.

in the step 3, the average grain size of the ingot is 0.551mm as shown in fig. 14, which is observed after the ingot is subjected to anodic coating.

Example 11

An Al-V-B master alloy and a method for preparing the same as in example 3.

in the step 3, after the anode coating of the cast ingot, the average grain size of the cast ingot is 1.147mm, as shown in fig. 15.

Example 12

An Al-V-B master alloy and a method for preparing the same as in example 4.

in the step 3, after the ingot is subjected to anodic coating, the average grain size of the ingot is 0.846mm, as shown in fig. 16.

In the above examples, for better observation of the as-cast microstructure, the ingot was subjected to anodic coating and then observed. The microscopic structure is observed by a metallographic microscope (type LeicaDMR); the adopted X-ray diffraction observation equipment is a polycrystalline X-ray diffractometer (model XPertpro); the process of anode coating is as follows: and (3) making the cast ingot into a plate shape to be used as an anode, and placing the plate into a furnace, wherein the mass concentration of a sulfuric acid solution is 98%, the mass concentration of a phosphoric acid solution is 50% and water are mixed according to the weight ratio of 2: 2: 1 for 20 seconds, and an anode voltage at the time of electrolysis of 20V, and a coating film was formed on the surface of the anode after the completion of electrolysis.

Claims

1. The Al-V-B intermediate alloy is characterized in that the chemical element composition of the intermediate alloy is as follows by mass percent: 2-3%, B: 1-2% and the balance of Al.

2. The Al-V-B master alloy of claim 1, wherein said master alloy comprises: Al-2V-1B master alloy, Al-2V-2B master alloy, Al-3V-1B master alloy, and Al-3V-2B master alloy.

3. The method for preparing an Al-V-B master alloy according to claim 1, comprising the steps of:

and step 3: heating the mixed meltKeeping the temperature for 1-1.5 h when the temperature reaches 810 +/-10 ℃, heating to 850 +/-10 ℃ after heat preservation, continuing keeping the temperature for 30-40 min, and stirring once every 10-15 min during the period to ensure uniform melting; after the temperature is reduced to 800 +/-10 ℃, the temperature is preserved for 30-40 min, and the mixture is stirred once every 10-15 min during the period to reduce particle agglomeration and sedimentation and prevent B from being in gaseous BF₃Form loss;

4. The method for preparing Al-V-B master alloy according to claim 3, wherein in the step 1, KBF is performed₄The particle size of the powder is 85-100 μm.

5. The method for preparing the Al-V-B intermediate alloy as claimed in claim 3, wherein in the step 2, the purity of the pure aluminum is more than or equal to 99.9%.

6. The method for preparing the Al-V-B intermediate alloy as claimed in claim 3, wherein the stirring rod is made of titanium, and the surface of the stirring rod is coated with the boron nitride coating.

7. Use of an Al-V-B master alloy according to claim 1 for grain refinement of aluminium or aluminium alloys.

8. The method for applying the Al-V-B master alloy as set forth in claim 1, which comprises the steps of:

and step 3: and heating the mixed melt to 720 +/-5 ℃, preserving the heat for 10-15 min, and then casting into an ingot.

9. The method for applying the Al-V-B intermediate alloy as claimed in claim 8, wherein in the step 2, the addition amount of the Al-V-B intermediate alloy is 0.1-0.2% by mass of V based on the total mass of the mixed melt.

10. The application method of the Al-V-B master alloy as claimed in claim 8, wherein in the step 3, the average grain diameter of the cast ingot is 0.202-1.147 mm.