CN106834876B - One kind is containing foundry returns aluminium alloy refining agent and its application method at high proportion - Google Patents

Abstract

The invention discloses a refining agent for aluminum alloys containing a high proportion of returned charge and a method for using the same. The refining agent includes general components and functional components, and the general components include chloride metal salts, fluorine metal salts, and fluoroaluminate Or one or two of fluorosilicates; functional components include the following components: niobium alloy, copper alloy, metal zinc, rare earth. After the refining agent of the present invention is added to the aluminum alloy melt containing a high proportion of recycled materials, it can fully diffuse from bottom to top without adsorption and agglomeration, quickly exerts the refining effect, and obtains a high-purity aluminum alloy melt. When it is used to refine aluminum alloy melt containing a high proportion of returned materials, the hydrogen content of the aluminum melt can be reduced to a level not exceeding 0.10ml/100g Al, and the total oxygen content of the aluminum melt can be reduced to 80ppm. In addition to its excellent degassing and impurity removal effects, the refining agent can also significantly reduce the number and size of β-Al ₅ FeSi phase in the casting structure, and eliminate the harmful effect of impurity iron in aluminum alloys, thereby improving the quality of cast aluminum alloy castings. mechanical properties and yield.

Description

Refining agent for aluminum alloy containing high proportion of returned materials and its application method

technical field

The invention relates to the smelting and processing technology of cast aluminum alloy, more particularly, refers to a refining agent for aluminum alloy containing a high proportion of recycled material and its application method. The refining agent can make the aluminum alloy return material be recycled as a resource.

Background technique

With the rapid development of the automobile industry, energy, environment and safety issues are becoming increasingly prominent, and the demand for aluminum alloys is increasing. The development and application of high-performance aluminum alloy parts to meet the needs of lightweight design is becoming more and more urgent. Cast aluminum alloy has become a widely used material for auto parts due to its excellent casting fluidity, physical properties, corrosion resistance and machinability. However, in the production process of aluminum alloy castings, due to the corrosion of raw materials to form "aluminum rust", the aluminum melt reacts with water, oxygen in the air, or the crucible lining for smelting, etc., resulting in the formation of oxide inclusions and gases, of which hydrogen accounts for More than 85% of the total gas. These inclusions and gases will cause a series of defects in the casting, resulting in a decrease in the performance of the casting, or even scrapping. Therefore, obtaining a clean aluminum alloy is one of the key technologies for preparing high-quality castings.

"Melt purification treatment, also called refining, is a process of removing inclusions and gases in the melt by various means. The purpose is to make the melt pure and an important measure to ensure high-quality castings (ingots)." "The flux used in the purification of aluminum alloy melts is mainly a mixture of alkali metal chloride salts and fluorine salts, which is called refining agent in the market." Edited by Tian Rongzhang, Casting Aluminum Alloys, Central South University Press, 2006.9, P196, P207-208 . Currently commercially available refining agents can reduce the hydrogen content of aluminum melts to a level of 0.2ml/100g Al.

However, as society’s demand for recycling of resources increases and competition in the aluminum alloy processing industry intensifies, many factories often add a high proportion of recycled materials when casting aluminum alloy parts (such as automobile wheels), or even Some return materials with higher oxide impurity content are also used. These recycled materials are mainly scraps, scraps, scrap castings, etc. produced in the process of preparing aluminum alloy castings. Their application results in insufficient degassing and impurity removal effects of ordinary commercially available refining agents during the refining of aluminum alloys, especially for the removal of small-sized The effect of inclusions is poor, the separation of aluminum slag is poor, and the resulting castings have many defects.

In addition, due to the use of a high proportion of recycled materials, the content of impurity iron in the aluminum melt increases significantly, and a large number of large-sized iron-rich phases appear in the solidification structure of the alloy, especially the needle-like β-Al ₅ FeSi phase, which significantly reduces the Al content. The mechanical properties and machining properties of alloy castings have a great influence on the qualified rate of products. Therefore, there is an urgent need to develop new high-efficiency refining agents to obtain high-quality ultra-pure cast aluminum alloy castings.

Contents of the invention

In order to solve the recycling of aluminum alloy castings, the traditional refining agent has poor purification effect on the aluminum alloy melt added with a high proportion of recycled materials, and a large number of large-sized needle-shaped harmful iron-rich phases are easily formed in the resulting casting structure, thereby deteriorating the casting. In order to solve the problem of performance, the present invention proposes a refining agent for aluminum alloy containing a high proportion of returned charge and its application method. The refining agent is made of alkali metal, chloride salt, fluoride salt, aluminum copper, aluminum niobium master alloy, metal zinc and rare earth elements in a reasonable proportion, and the use method is simple and easy. After the refining agent is added to the aluminum melt, it can fully diffuse from bottom to top without adsorption and agglomeration, and quickly exerts the refining effect to obtain high-purity aluminum alloy melt. When it is used to refine the aluminum alloy melt containing a high proportion of returned materials, the hydrogen content of the aluminum melt can be reduced to a level of no more than 0.10ml/100g Al, and the total oxygen content of the aluminum melt can be reduced to no more than 80ppm. Level. In addition to its excellent degassing and impurity removal effects, the refining agent can also significantly reduce the number and size of β-Al ₅ FeSi phase in the casting structure, and eliminate the harmful effect of impurity iron in aluminum alloys, thereby improving the quality of cast aluminum alloy castings. mechanical properties and yield.

The complete technical scheme of the present invention comprises:

A refining agent for aluminum alloys containing a high proportion of returned charge, the refining agent includes general-purpose components and functional components, characterized in that: the general-purpose components include the following components: chloride metal salt, fluorine metal salt, fluorine metal salt Aluminate and/or fluorosilicate; said functional component includes the following components: niobium alloy, copper alloy, metal zinc and rare earth.

Preferably, in the refining agent, the mass fraction of universal components is 54%-91%, and the mass fraction of functional components is 14%-36%.

Preferably, the metal chloride salt is a combination of alkali metal salt, MnCl ₂ , and MgCl ₂ , the fluoroaluminate or fluorosilicate is Na ₃ AlF ₆ or Na ₃ SiF ₆ , and the metal fluoride The salt is _CaF2 .

Preferably, the niobium alloy is Al-10Nb alloy.

Preferably, the copper alloy is Al ₂ Cu alloy.

Preferably, the rare earth RE is one or a mixture of two or more of La, Ce, Nd and Er.

Preferably, the refining agent is specifically composed of the following components in mass fractions;

The sum of the above combinations is 100wt%.

The rare earth RE is one or a mixture of two or more of La, Ce, Nd and Er.

The method for preparing the described refining agent for aluminum alloy containing a high proportion of recycled materials has the following steps:

Step A, mix NaCl, Na ₃ AlF ₆ , Al10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into a melting furnace, heat up and melt, keep it warm, then cool the mixture, take it out and break it into granules, Prepare the premix;

Step B, uniformly mix the premixed material obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE and a binder according to the target composition of the refining agent, and press it into an ingot to obtain an ingot-shaped refining agent.

The method for using the refining agent for aluminum alloys containing a high proportion of returned materials is to use the ingot-shaped refining agent in the industrial production of aluminum alloy castings, and the addition amount of the ingot-shaped refining agent accounts for 0.05-0.20 wt% of the aluminum alloy mass .

In the method for using the refining agent for aluminum alloy containing a high proportion of recycled material, the recycled material accounts for 40wt%-100wt% of the total mass of the aluminum alloy.

The method for using the refining agent for aluminum alloy containing a high proportion of recycled materials specifically includes the following steps:

Step 1: melting the recycle material and the new aluminum alloy material to be used in the smelting furnace, and transferring the molten aluminum to the tundish after the composition is adjusted to pass;

Step 2: After putting the Al-10Sr modifier and Al-5Ti-B refiner into the tundish, directly put the ingot-shaped refining agent into the tundish, so that the ingot-shaped refining agent can freely sink into the bottom of the molten aluminum;

Step 3, after adding the refining agent into the tundish, purging and refining the aluminum melt with inert gas;

Step 4: After refining, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the casting process is used to prepare aluminum alloy castings.

According to the method of using the refining agent for aluminum alloy containing a high proportion of recycled materials, the H content of the aluminum liquid obtained after refining with the refining agent is reduced to no more than 0.10ml/100g Al, and the total oxygen content is reduced to no more than 80ppm.

For the aluminum alloy part obtained by the method, the recycled materials used in the preparation of the aluminum alloy part account for 40wt%-100wt% of the total mass of the aluminum alloy.

The part is a wheel, and the elongation rate of the spoke and the inner rim of the aluminum alloy wheel made by refining the aluminum liquid obtained by refining with a refining agent is increased by 20-40%.

Compared with the prior art, using the refining agent of the present invention when casting aluminum alloy parts has the following advantages:

(1) The refining agent of the present invention has excellent degassing, impurity and slag removal effects, and can obtain ultra-pure cast aluminum alloys. When using it to refine aluminum alloys containing a high proportion of recycled materials or aluminum alloy melts composed entirely of recycled materials, the hydrogen (H) content of the aluminum melt can be reduced to a level not exceeding 0.10ml/100g Al; the aluminum melt The total oxygen (O) content is reduced to a level not exceeding 80ppm.

(2) The refining agent obtained in the present invention is in the shape of a round ingot instead of a traditional powder, and the method of use is simple and easy. After the refining agent is placed in the aluminum melt, the refining agent can fully diffuse from bottom to top without adsorption and agglomeration, and can quickly exert the refining effect, which not only solves the problem of the traditional powder refining agent floating on the surface of the aluminum liquid and has insufficient refining effect, It also avoids complicated processes such as pressing the bell jar and cleaning the filter disc, thereby reducing labor intensity.

(3) Compared with ordinary commercially available refining agents, the refining agent of the present invention significantly reduces the content and size of brittle iron-rich phases, and effectively eliminates the harmful effects of impurity iron.

(4) Compared with common commercially available refining agents, after using the refining agent of the present invention, the properties of the obtained castings are significantly improved, for example, the elongation of the spokes and inner rims of low-pressure cast aluminum alloy wheels can be increased by 20-40%.

(5) Compared with ordinary commercially available refining agents, the refining agent of the present invention significantly improves the yield of cast aluminum alloy castings, especially significantly improves the yield of aluminum alloy castings containing a high proportion of recycled materials.

Description of drawings

Fig. 1 is a tensile curve diagram of the spoke part of the B1 wheel.

Fig. 2 is a tensile curve diagram of the inner rim of the B1 wheel.

Fig. 3 is a tensile curve diagram of the spoke portion of the A1 wheel.

Fig. 4 is a tensile curve diagram of the inner rim of the A1 wheel.

Figure 5 is a photo of the microstructure of the spokes of the B1 wheel.

Figure 6 is a photo of the microstructure of the spokes of the A1 wheel.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

In the present invention, the recycled materials to be used refer to scraps, waste materials, scrap castings, etc. generated during the process of preparing A356 aluminum alloy castings.

In the present invention, the unused recycled material used in the preparation of the aluminum alloy wheel reaches 40wt%-100wt%, which effectively realizes resource recycling of the unused recycled material.

In the present invention, molten aluminum A is obtained by refining the recycled materials and new aluminum alloy materials with the refining agent prepared in the present invention.

In the present invention, molten aluminum B is obtained by refining the recycled material and the new aluminum alloy material to be used with a commercially available refining agent. In the same embodiment, the ratio of recycled material to be used in aluminum liquid B to aluminum alloy new material is consistent with that of aluminum liquid A; the content of refining agent used in aluminum liquid B is consistent with that of aluminum liquid A.

The complete technical scheme of the present invention comprises:

A refining agent for aluminum alloys containing a high proportion of returned charge, the refining agent includes general-purpose components and functional components, characterized in that: the general-purpose components include the following components: chloride metal salt, fluorine metal salt, fluorine metal salt Aluminate and/or fluorosilicate; said functional component includes the following components: niobium alloy, copper alloy, metal zinc and rare earth.

Preferably, in the refining agent, the mass fraction of universal components is 54%-91%, and the mass fraction of functional components is 14%-36%.

Preferably, the metal chloride salt is a combination of alkali metal salt, MnCl ₂ , and MgCl ₂ , the fluoroaluminate or fluorosilicate is Na ₃ AlF ₆ or Na ₃ SiF ₆ , and the metal fluoride The salt is _CaF2 .

Preferably, the niobium alloy is Al-10Nb alloy.

Preferably, the copper alloy is Al ₂ Cu alloy.

Preferably, the rare earth RE is one or a mixture of two or more of La, Ce, Nd and Er.

Composition of refining agent:

A refining agent for aluminum alloys containing a high proportion of recycled materials according to the present invention, the refining agent is composed of the following components in mass fractions:

The sum of the above combinations is 100wt%.

The rare earth RE is one or a mixture of two or more of La, Ce, Nd and Er.

Preparation of refining agent:

The step of preparing refining agent of the present invention has:

Step A, mix NaCl, Na ₃ AlF ₆ , Al-10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into a melting furnace, and raise the temperature at a rate of 20°C/min. When the temperature rises to 800~ 820°C, keep warm for 10 minutes, turn off the power, cool the mixture to room temperature, take it out and break it into 1-5mm particles to prepare the premix;

Step B: Mix the premix obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE and binders evenly according to the target composition of the refining agent, and use a hydraulic press to press under the pressure parameters of 20-30KN Form a round ingot with a density greater than 3g/ ^cm3 and a mass of 0.25kg to obtain a round ingot-shaped refining agent.

The target composition of described refining agent is:

How to use refining agent

The ingot-shaped refining agent is used in the industrial production of aluminum alloy castings by adopting a low-pressure casting process, and the added content of the ingot-shaped refining agent is 0.05-0.20 wt%.

Step 1: Melt the recycled materials and new aluminum alloy materials in the smelting furnace, and transfer the molten aluminum into a 1-ton tundish after the components are adjusted to pass;

Step 2, after putting Al-10Sr modifier and Al-5Ti-B refiner into the tundish, directly put the round ingot-shaped refining agent of the present invention into the tundish, so that the round ingot-shaped refining agent can sink freely into the molten aluminum bottom;

Step 3: After adding the refining agent to the tundish, start to use the GBF device to purge the aluminum melt with inert gas, the inert gas used is N ₂ with a volume percentage of 99.5%, the purging and refining temperature is 710-730°C, and the refining time is 12～18min;

Step 4: After the refining is completed, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the low-pressure casting process is used to prepare aluminum alloy castings.

In the present invention, after the ingot-shaped refining agent is directly placed in the aluminum melt, the refining agent can be fully diffused from bottom to top, without adsorption and agglomeration, and can quickly play a role in refining, which not only solves the problem of traditional powder refining agent floating in the aluminum melt The surface and the problem of insufficient refining effect also avoid complicated processes such as pressing the bell jar and cleaning the filter disc, which reduces the labor intensity.

Example 1

The preparation steps of embodiment 1 refining agent have:

Step A, mix the weighed NaCl, Na ₃ AlF ₆ , Al10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into the melting furnace, and raise the temperature at a rate of 20°C/min. When the temperature rises to 810°C, keep warm for 10 minutes, turn off the power, cool the mixture to room temperature, take it out and break it into 1-5mm particles to prepare the premix;

Step B, mix the premix obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE (that is, La, Ce and Nd) and binder according to the target composition of the refining agent, and use a YL41 hydraulic press , under the pressure parameter of 25KN, press it into a round ingot with a density of 3.2g/cm ³ and a mass of 0.25kg to obtain a round ingot-shaped refining agent.

The target composition of the refining agent of embodiment 1 is:

Embodiment 1 makes the using method of refining agent:

The refining agent of Example 1 was used in the industrial production of A356 aluminum alloy wheels by low-pressure casting process, and the added content of the refining agent of Example 1 was 0.15 wt%. The raw materials required for the A356 aluminum alloy wheel are 80wt% recycled material to be utilized and 20wt% new A356 aluminum alloy material.

Step 1: Melt the raw materials required for the A356 aluminum alloy wheel in the melting furnace, and transfer the molten aluminum into a 1-ton tundish after the composition is adjusted to pass;

Step 2: After putting Al-10Sr modifier and Al-5Ti-B refiner into the tundish, the ingot-shaped refining agent of Example 1 is directly put into the tundish, and the refining agent freely sinks into the molten aluminum body bottom;

Step 3: After adding the refining agent to the tundish, start to use the GBF device to purge the aluminum melt with inert gas, the inert gas used is N ₂ with a volume percentage of 99.5%, the purging and refining temperature is 720°C, and the refining time is 15 minutes;

Step 4: After refining, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the low-pressure casting process is used to prepare A356 aluminum alloy wheels.

Using the refining agent in Example 1 can effectively remove the oxidized inclusions, and the separation of aluminum slag is good. Perform decompression solidification analysis on the aluminum liquid A, and use the LY-CQ-1 model aluminum water hydrogen detector to detect, and the measured hydrogen content in the aluminum liquid A can drop to the level of 0.08ml/100g Al; use the LECO O836 model oxygen analyzer According to the test, the total oxygen content is reduced to 60ppm, and the purification effect is good.

Embodiment 1 For the low-pressure casting process, please refer to "Casting Technology of Aluminum Alloy Wheels", Zhao Yutao, Machinery Industry Press, 1st edition in July 2004, pages 91-92. in:

The pouring temperature is 700°C;

The hydraulic pressure is 0.020MPa, and the pressurization speed is 0.0014MPa/s;

The filling pressure is 0.050MPa, and the pressurization speed is 0.0020MPa/s;

The boost pressure is 0.10MPa, and the boost speed is 0.050MPa/s;

The holding pressure is 0.10MPa, and the holding time is 160s;

Open the mold 240s after pouring.

Set the above-mentioned low-pressure casting process parameters on the low-pressure casting machine, pour aluminum liquid A into the mold to make A356 aluminum alloy wheels, and the obtained wheels are recorded as A1 wheels.

Set the above-mentioned low-pressure casting process parameters on the low-pressure casting machine, pour the aluminum liquid B into the mold to make the A356 aluminum alloy wheel, and the obtained wheel is denoted as B1 wheel.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) is used to detect the mechanical properties of the spokes and the inner rim of the B1 wheel: the tensile strength of the spokes is 250MPa, and the elongation is 4.1% (as shown in Figure 1); the tensile strength of the inner rim is 280MPa, the elongation is 7.8% (as shown in Figure 2). The electron probe (JXA-8100) was used to observe the microstructure of the spokes of the B1 wheel, and there were a large number of long needle-like bright white β-Fe phases and oxide inclusions (as shown in Figure 5).

Hydraulic servo fatigue testing machine (Instron8801, 50KN) is used to detect the mechanical properties of the spokes and inner rim of the A1 wheel: the tensile strength of the spokes is increased to 255MPa, and the elongation is increased to 5.8% (as shown in Figure 3); the tensile strength of the inner rim Strength 300MPa, elongation increased to 11.7% (as shown in Figure 4). Using an electron probe (JXA-8100) to observe the microstructure of the spokes of the A1 wheel, it was found that the oxide inclusions were significantly reduced, and the number and size of the long needle-like bright white β-Fe phase were significantly reduced (as shown in Figure 6 ); the long acicular iron phase is eliminated, which reduces the splitting effect on the aluminum alloy structure and reduces the damage to the mechanical properties of the wheel. By comparing the A1 wheel with the B1 wheel, since the refining agent in Example 1 can fully diffuse after entering the aluminum alloy melt containing 80wt% recycled material to be used, without adsorption and agglomeration, the H content of the aluminum liquid A can be reduced to about 0.08ml/ At the level of 100g Al, the total oxygen content is reduced to the level of 60ppm, which can fully remove the oxidized inclusions in the aluminum liquid A. Just because of the addition of the refining agent of the present invention, the A1 wheel has good mechanical properties.

Example 2

The preparation steps of embodiment 2 refining agent have:

Step A, mix the weighed NaCl, Na ₃ AlF ₆ , Al10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into the melting furnace, and raise the temperature at a rate of 20°C/min. When the temperature rises to 800°C, keep warm for 10 minutes, turn off the power, cool the mixture to room temperature, take it out and break it into 1-5mm particles to prepare the premix;

Step B, mix the premix obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE (that is, La, Ce and Er) and binder according to the target composition of the refining agent, and use a YL41 hydraulic press , under the pressure parameter of 24KN, press it into a round ingot with a density of 3.1g/cm ³ and a mass of 0.25kg to obtain a round ingot-shaped refining agent.

The target composition of the refining agent of embodiment 2 is:

Embodiment 2 makes the using method of refining agent:

The refining agent of Example 2 was used in the industrial production of A356 aluminum alloy wheels by low-pressure casting process, and the added content of the refining agent of Example 2 was 0.13wt%. The raw materials required for the A356 aluminum alloy wheel are 70wt% recycled material to be utilized and 30wt% new A356 aluminum alloy material.

Step 1: Melt the raw materials required for the A356 aluminum alloy wheel in the melting furnace, and transfer the molten aluminum into a 1-ton tundish after the composition is adjusted to pass;

Step 2: After putting Al-10Sr modifier and Al-5Ti-B refiner into the tundish, the ingot-shaped refining agent of Example 2 is directly put into the tundish, and the refining agent freely sinks into the molten aluminum body bottom;

Step 3: After adding the refining agent to the tundish, start to use the GBF device to purge the aluminum melt with inert gas, the inert gas used is N ₂ with a volume percentage of 99.5%, the purging and refining temperature is 715°C, and the refining time is 16 minutes;

Step 4: After refining, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the low-pressure casting process is used to prepare A356 aluminum alloy wheels.

Using the refining agent in Example 2 can effectively remove the oxidized inclusions, and the separation of aluminum slag is good. Carry out decompression solidification analysis on aluminum liquid A, and use LY-CQ-1 model aluminum water hydrogen detector to detect, and the measured hydrogen content in aluminum liquid A can drop to the level of 0.07ml/100g Al; use LECO O836 model oxygen analyzer According to the test, the total oxygen content has dropped to 67ppm, and the purification effect is good.

Embodiment 2 For the low-pressure casting process, please refer to "Casting Technology of Aluminum Alloy Wheels", Zhao Yutao, Machinery Industry Press, 1st edition in July 2004, pages 91-92. in:

The pouring temperature is 700°C;

The hydraulic pressure is 0.020MPa, and the pressurization speed is 0.0014MPa/s;

The filling pressure is 0.050MPa, and the pressurization speed is 0.0020MPa/s;

The boost pressure is 0.10MPa, and the boost speed is 0.050MPa/s;

The holding pressure is 0.10MPa, and the holding time is 160s;

Open the mold 240s after pouring.

The above-mentioned low-pressure casting process parameters are set on the low-pressure casting machine, and the aluminum liquid A is injected into the mold to make an A356 aluminum alloy wheel, and the obtained wheel is recorded as an A2 wheel.

The above-mentioned low-pressure casting process parameters are set on the low-pressure casting machine, and the aluminum liquid B is injected into the mold to make an A356 aluminum alloy wheel, and the obtained wheel is recorded as a B2 wheel.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) was used to detect the mechanical properties of the spokes and inner rim of the B2 wheel: the tensile strength of the spokes was 245MPa, and the elongation was 4.0%; the tensile strength of the inner rim was 275MPa, and the elongation was 7.6% . The electron probe (JXA-8100) was used to observe the microstructure of the spokes of the B2 wheel, and there were a large number of long needle-like bright white β-Fe phases and oxide inclusions.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) is used to detect the mechanical properties of the spokes and inner rim of the A2 wheel: the tensile strength of the spokes is increased to 260MPa, and the elongation is increased to 5.5%; the tensile strength of the inner rim is 295MPa, and the elongation is increased to 11.2%. Using an electron probe (JXA-8100) to observe the microstructure of the spokes of the A2 wheel, it was found that the oxide inclusions were significantly reduced, and the number and size of the long acicular bright white β-Fe phase were significantly reduced; the long acicular iron phase It is eliminated, which reduces the splitting effect on the aluminum alloy structure and reduces the damage to the mechanical properties of the wheel. By comparing the A2 wheel with the B2 wheel, since the refining agent in Example 2 can fully diffuse after entering the aluminum alloy melt containing 70wt% recycled material to be used, without adsorption and agglomeration, the H content of the aluminum liquid A can be reduced to about 0.07ml/ At the level of 100g Al, the total oxygen content is reduced to the level of 67ppm, which can fully remove the oxidized inclusions in the aluminum liquid A. Just because of the addition of the refining agent of the present invention, the A2 wheel has good mechanical properties.

Example 3

The preparation steps of embodiment 3 refining agent have:

Step A, mix the weighed NaCl, Na ₃ AlF ₆ , Al10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into the melting furnace, and raise the temperature at a rate of 20°C/min. When the temperature rises to 820°C, keep warm for 10 minutes, turn off the power, cool the mixture to room temperature, take it out and break it into 1-5mm particles to prepare the premix;

Step B, mix the premix obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE (that is, La, Ce, Nd and Er) and binder according to the target composition of the refining agent, and use YL41 model Under the pressure parameter of 27KN, it is compressed into a round ingot with a density of 3.3g/cm ³ and a mass of 0.25kg to obtain a round ingot-shaped refining agent.

The composition that embodiment 3 makes refining agent is:

Embodiment 3 makes the using method of refining agent:

The refining agent of Example 3 was used in the industrial production of A356 aluminum alloy wheels by low-pressure casting process, and the added content of the refining agent of Example 3 was 0.10 wt%. The raw materials required for the A356 aluminum alloy wheel are 65wt% recycled material to be utilized and 35wt% new A356 aluminum alloy material.

Step 1: Melt the raw materials required for the A356 aluminum alloy wheel in the melting furnace, and transfer the molten aluminum into a 1-ton tundish after the composition is adjusted to pass;

Step 2: After putting Al-10Sr modifier and Al-5Ti-B refiner into the tundish, the round ingot-shaped refining agent of Example 3 is directly put into the tundish, and the refining agent freely sinks into the molten aluminum body bottom;

Step 3: After adding the refining agent to the tundish, start to use the GBF device to purging the aluminum melt with an inert gas, the inert gas used is N ₂ with a volume percentage of 99.5%, the purging and refining temperature is 710°C, and the refining time is 14 minutes;

Step 4: After refining, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the low-pressure casting process is used to prepare A356 aluminum alloy wheels.

Using the refining agent in Example 3 can effectively remove the oxidized inclusions, and the separation of aluminum slag is good. Perform decompression solidification analysis on the aluminum liquid A, and use the LY-CQ-1 model aluminum water hydrogen detector to detect, and the measured hydrogen content in the aluminum liquid A can drop to the level of 0.09ml/100g Al; use the LECO O836 model oxygen analyzer According to the test, the total oxygen content has dropped to 72ppm, and the purification effect is good.

Embodiment 3 For the low-pressure casting process, please refer to "Casting Technology of Aluminum Alloy Wheels", Zhao Yutao, Machinery Industry Press, first edition in July 2004, pages 91-92. in:

The pouring temperature is 700°C;

The hydraulic pressure is 0.020MPa, and the pressurization speed is 0.0014MPa/s;

The filling pressure is 0.050MPa, and the pressurization speed is 0.0020MPa/s;

The boost pressure is 0.10MPa, and the boost speed is 0.050MPa/s;

The holding pressure is 0.10MPa, and the holding time is 160s;

Open the mold 240s after pouring.

The above-mentioned low-pressure casting process parameters are set on the low-pressure casting machine, and the aluminum liquid A is injected into the mold to make an A356 aluminum alloy wheel, and the obtained wheel is recorded as an A3 wheel.

Set the above-mentioned low-pressure casting process parameters on the low-pressure casting machine, pour aluminum liquid B into the mold to make A356 aluminum alloy wheels, and the obtained wheels are denoted as B3 wheels.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) was used to detect the mechanical properties of the spokes and inner rim of the B3 wheel: the tensile strength of the spokes was 242MPa, and the elongation was 4.0%; the tensile strength of the inner rim was 273MPa, and the elongation was 7.5% . Electron probe (JXA-8100) was used to observe the microstructure of the spokes of the B3 wheel, and there were a large number of long needle-like bright white β-Fe phases and oxide inclusions.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) was used to detect the mechanical properties of the spokes and inner rim of the A3 wheel: the tensile strength of the spokes was increased to 257MPa, and the elongation was increased to 5.1%; the tensile strength of the inner rim was 293MPa, and the elongation was increased to 10.1%. Using the electron probe (JXA-8100) to observe the microstructure of the spokes of A3 wheels, it was found that the oxide inclusions were significantly reduced, and the number and size of the long acicular bright white β-Fe phase were significantly reduced; in the long acicular iron When the phase is eliminated, the splitting effect on the aluminum alloy structure is reduced, and the damage to the mechanical properties of the wheel is reduced. By comparing the A3 wheel with the B3 wheel, since the refining agent in Example 3 enters the aluminum alloy melt containing 65wt% recycled material to be used, it can fully diffuse without adsorption and agglomeration, and the H content of the aluminum liquid A can be reduced to about 0.09ml/ At the level of 100g Al, the total oxygen content is reduced to the level of 72ppm, which can fully remove the oxidized inclusions in the aluminum liquid A. Just because of the addition of the refining agent of the present invention, the A3 wheel has good mechanical properties.

Example 4

The preparation steps of embodiment 4 refining agent have:

Step A, mix the weighed NaCl, Na ₃ AlF ₆ , Al10Nb and Al ₂ Cu according to the target composition of the refining agent, stir evenly, put it into the melting furnace, and raise the temperature at a rate of 20°C/min. When the temperature rises to 815°C, keep warm for 10 minutes, turn off the power, cool the mixture to room temperature, take it out and break it into 1-5mm particles to prepare the premix;

Step B, according to the target composition of the refining agent, mix the premix obtained in step A with MnCl ₂ , MgCl ₂ , CaF ₂ , Zn, RE (that is, La and Ce) and binder, and use a YL41 hydraulic press to Under the pressure parameter of 26KN, press it into a round ingot with a density of 3.2g/cm ³ and a mass of 0.25kg to obtain a round ingot-shaped refining agent.

The target composition of the refining agent of embodiment 4 is:

Embodiment 4 makes the using method of refining agent:

The refining agent of Example 4 was used in the industrial production of A356 aluminum alloy wheels by low-pressure casting process, and the added content of the refining agent of Example 4 was 0.20 wt%. The raw material required for the A356 aluminum alloy wheel is 100wt% recycled material to be utilized.

Step 1: Melt the raw materials required for the A356 aluminum alloy wheel in the melting furnace, and transfer the molten aluminum into a 1-ton tundish after the composition is adjusted to pass;

Step 2: After putting Al-10Sr modifier and Al-5Ti-B refiner into the tundish, the ingot-shaped refining agent of Example 4 is directly put into the tundish, and the refining agent freely sinks into the molten aluminum body bottom;

Step 3: After adding the refining agent to the tundish, start to use the GBF device to purge the aluminum melt with inert gas, the inert gas used is N ₂ with a volume percentage of 99.5%, the purging and refining temperature is 720°C, and the refining time is 17 minutes;

Step 4: After refining, the slag is removed from the tundish, and the refined aluminum liquid in the tundish is poured into the holding furnace, and the low-pressure casting process is used to prepare A356 aluminum alloy wheels.

Using the refining agent of Example 4 can effectively remove the oxidized inclusions, and the separation of aluminum slag is good. Perform decompression solidification analysis on aluminum liquid A, and use LY-CQ-1 type aluminum water hydrogen detector for detection, and the measured hydrogen content in aluminum liquid A can drop to the level of 0.09ml/100gAl; use LECO O836 model oxygen analyzer for detection , the total oxygen content drops to the level of 78ppm, and the purification effect is good.

Embodiment 4 For the low-pressure casting process, please refer to "Casting Technology of Aluminum Alloy Wheels", Zhao Yutao, Machinery Industry Press, first edition in July 2004, pages 91-92. in:

The pouring temperature is 700°C;

The hydraulic pressure is 0.020MPa, and the pressurization speed is 0.0014MPa/s;

The filling pressure is 0.050MPa, and the pressurization speed is 0.0020MPa/s;

The boost pressure is 0.10MPa, and the boost speed is 0.050MPa/s;

The holding pressure is 0.10MPa, and the holding time is 160s;

Open the mold 240s after pouring.

Set the above-mentioned low-pressure casting process parameters on the low-pressure casting machine, pour aluminum liquid A into the mold to make A356 aluminum alloy wheels, and the obtained wheels are recorded as A4 wheels.

Set the above-mentioned low-pressure casting process parameters on the low-pressure casting machine, pour aluminum liquid B into the mold to make A356 aluminum alloy wheels, and the obtained wheels are denoted as B4 wheels.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) was used to detect the mechanical properties of the spokes and inner rim of the B4 wheel: the tensile strength of the spokes was 240MPa, and the elongation was 3.8%; the tensile strength of the inner rim was 270MPa, and the elongation was 7.2% . Electron probe (JXA-8100) was used to observe the microstructure of the spokes of B4 wheels, and there were a large number of long needle-like bright white β-Fe phases and oxide inclusions.

Hydraulic servo fatigue testing machine (Instron8801, 50KN) was used to detect the mechanical properties of the spokes and inner rim of the A4 wheel: the tensile strength of the spokes was increased to 251MPa, and the elongation was increased to 4.9%; the tensile strength of the inner rim was 290MPa, and the elongation was increased to 9.8%. Using an electron probe (JXA-8100) to observe the microstructure of the spokes of the A4 wheel, it was found that the oxide inclusions were significantly reduced, and the number and size of the long acicular bright white β-Fe phase were significantly reduced; the long acicular iron phase It is eliminated, which reduces the splitting effect on the aluminum alloy structure and reduces the damage to the mechanical properties of the wheel. By comparing the A4 wheel with the B4 wheel, since the refining agent in Example 4 enters the aluminum alloy melt containing 100wt% recycled material to be used, it can fully diffuse without adsorption and agglomeration, and the H content of the aluminum liquid A can be reduced to about 0.09ml/ At the level of 100g Al, the total oxygen content is reduced to the level of 78ppm, which can fully remove the oxide inclusions in the aluminum liquid A. Just because of the addition of the refining agent of the present invention, the A4 wheel has good mechanical properties.

Claims (12)

1. one kind includes general component and function ingredients containing foundry returns aluminium alloy refining agent, the refining agent at high proportion, it is special Sign is：

Described common group point includes following components：Chlorine metal salt, fluorine metal salt, fluoaluminate and/or fluosilicate；

Described function ingredients include following components：Niobium alloy, copper alloy, metallic zinc and rare earth；

Described refining agent is specifically made up of each component of following mass fraction；

Combination of the above sum is 100wt%.

2. the refining agent described in claim 1, it is characterised in that the chlorine metal salt is alkali metal salt, MnCl₂、MgCl₂Group Compound, described fluoaluminate or fluosilicate are Na₃AlF₆Or Na₃SiF₆, described fluorine metal salt is CaF₂。

3. the refining agent described in claim 1, it is characterised in that described niobium alloy is Al-10Nb alloys.

4. the refining agent described in claim 1, it is characterised in that described copper alloy is Al₂Cu alloys.

5. the refining agent described in claim 1, it is characterised in that the rare earth RE is one or both of La, Ce, Nd and Er And two or more mixing.

6. a kind of method containing foundry returns aluminium alloy refining agent at high proportion prepared described in any one of Claims 1 to 5, it is special Sign is there are the following steps：

Step A, according to the target component of refining agent by NaCl, Na₃AlF₆, Al10Nb and Al₂Cu is mixed, and is stirred, is inserted molten Change in stove, be incubated after heating fusing, then compound is cooled down, takes out and is broken into particle, premix is made；

Step B, according to the target component of refining agent by the obtained premixes of step A and MnCl₂、MgCl₂、CaF₂, Zn, RE and viscous Knot agent is well mixed, and is suppressed ingot, is obtained ingot shape refining agent.

7. the application method containing foundry returns aluminium alloy refining agent at high proportion according to any one of Claims 1 to 5, it is special Sign is：Ingot shape refining agent is used in the industrial production of aluminium alloy castings, the ingot shape refining agent addition accounts for aluminium alloy matter 0.05~0.20wt% of amount.

8. the application method containing foundry returns aluminium alloy refining agent at high proportion according to any one of Claims 1 to 5, it is special Sign is：Described foundry returns accounts for 40wt%~100wt% of aluminium alloy gross mass.

9. the application method containing foundry returns aluminium alloy refining agent at high proportion according to claim 7 or 8, its feature exist In specifically comprising the following steps：

Step 1, foundry returns to be utilized and aluminium alloy virgin material are melted in smelting furnace, are transferred to aluminium liquid after composition adjustment is qualified Tundish；

Step 2, it is after Al-10Sr alterants and Al-5Ti-B fining agents are put into tundish, ingot shape refining agent is direct Put into tundish, ingot shape refining agent is freely sunk to aluminium liquid bottom；

Step 3, after tundish adds refining agent, inert gas purging refining is carried out to aluminum melt；

Step 4, after refining, skimmed in bag, and the aluminium liquid after being refined in tundish is injected into holding furnace, started using casting Make technique and prepare aluminium alloy castings.

10. the application method according to claim 9 containing foundry returns aluminium alloy refining agent at high proportion, it is characterised in that： The H content that aluminium liquid is obtained after refined dose of refining is down to and is down to no more than 0.10ml/100gAl, total oxygen content no more than 80ppm.

11. obtained using described in any one of claim 7~10 containing foundry returns aluminium alloy at high proportion with the application method of refining agent The aluminium alloy part arrived, it is characterised in that：Foundry returns to be utilized used in the aluminium alloy part preparation accounts for the total matter of aluminium alloy 40wt%~100wt% of amount.

It is 12. according to claim 11 containing the aluminium alloy that foundry returns aluminium alloy is obtained with the application method of refining agent at high proportion Part, it is characterised in that：The aluminium alloy part is wheel, the aluminium alloy made using the aluminium liquid obtained after refined dose of refining The spoke and inner rim elongation percentage of wheel improve 20~40%.