阅读说明：本技术 一种铝钢固液双金属复合铸造的方法 (Aluminum steel solid-liquid bimetal composite casting method ) 是由 张国伟 王赵杰 王聪 刘毅军 万安 任晓燕 于 2021-09-11 设计创作，主要内容包括：本发明公开了一种铝钢固液双金属复合铸造的方法,属于双金属铸造技术领域；步骤为：在铝合金熔体加入Al-5Ti-0.5C中间合金并搅拌除气；之后将熔体升温到708℃-710℃；将预热好的钢基体放入砂型中,将超声装置的振动子进行预热后移到砂型中,开始浇注铝合金熔体；浇注完成后,开启超声振动；超声振动的频率为10KHz-20KHz,功率为1-3KW；超声振动的时间为10-40s；本发明方法有助于界面反应,并形成冶金结合,有效增加铝钢固液界面处的结合强度。(The invention discloses a method for composite casting of aluminum steel solid-liquid bimetal, belonging to the technical field of bimetal casting; the method comprises the following steps: adding Al-5Ti-0.5C intermediate alloy into the aluminum alloy melt, and stirring and degassing; then heating the melt to 708-710 ℃; placing the preheated steel matrix into a sand mold, preheating a vibrator of an ultrasonic device, moving the preheated vibrator into the sand mold, and beginning to cast an aluminum alloy melt; after the pouring is finished, starting ultrasonic vibration; the frequency of ultrasonic vibration is 10KHz-20KHz, and the power is 1-3 KW; the ultrasonic vibration time is 10-40 s; the method of the invention is beneficial to interface reaction, forms metallurgical bonding and effectively increases the bonding strength of the solid-liquid interface of the aluminum steel.)

1. The method for aluminum steel solid-liquid bimetal composite casting is characterized by comprising the following steps:

a) smelting aluminum alloy into liquid, adding Al-5Ti-0.5C intermediate alloy into the liquid, and stirring for degassing; the content of the Al-5Ti-0.5C intermediate alloy is 4.5-5% of the weight of the aluminum alloy;

b) putting the aluminum alloy liquid subjected to gas removal into a smelting furnace, and heating to 708-710 ℃;

c) placing the preheated steel matrix into a sand mold, preheating a vibrator of an ultrasonic device, moving the preheated vibrator into the sand mold, and beginning to pour aluminum alloy liquid;

d) after the pouring is finished, starting ultrasonic vibration; the frequency of ultrasonic vibration is 10KHz-20KHz, and the power is 1-3 KW; the time of ultrasonic vibration is 10-40 s.

2. The aluminum steel solid-liquid bimetal composite casting method according to claim 1, wherein the preheating temperature of the steel substrate is 150-250 ℃; the heat preservation time of the steel matrix is 2-3 min.

3. The method for composite casting of aluminum-steel solid-liquid bimetal according to claim 1, wherein the aluminum alloy liquid is obtained by putting aluminum alloy into a crucible and smelting in a smelting furnace, and the smelting temperature is 750-800 ℃.

4. The method for aluminum steel solid-liquid bimetal composite casting according to claim 1, wherein Ar gas is used for degassing the aluminum alloy melt.

5. The method for aluminum steel solid-liquid bimetal composite casting according to claim 1, wherein the degassed aluminum alloy melt is poured after being heated to 710 ℃.

6. The method for aluminum steel solid-liquid bimetal composite casting according to claim 1, wherein the preheating temperature of the vibrator is 660-710 ℃ and the preheating time is 2-3 min.

7. The method for aluminum steel solid-liquid bimetal composite casting according to claim 6, wherein the preheating temperature of the vibrator is 700 ℃ and the preheating time is 2 min.

8. The method for aluminum steel solid-liquid bimetal composite casting according to claim 1, wherein the depth of the vibrator submerged in the aluminum alloy melt is 20 mm.

9. The method for aluminum-steel solid-liquid bimetal composite casting according to claim 1, wherein the aluminum alloy material is ZL114A, and the steel matrix material is 45 steel.

10. The aluminum steel solid-liquid bimetal composite casting method according to claim 1, wherein after the ultrasonic vibration is finished, the vibrator is moved out of the liquid level and cooled to room temperature to obtain the aluminum steel bimetal composite material.

Technical Field

The invention belongs to the technical field of bimetal casting, and particularly relates to a method for aluminum steel solid-liquid bimetal composite casting.

Background

Because the aluminum-steel bimetal composite material has the advantages of excellent mechanical property of steel, corrosion resistance of aluminum material, good heat conduction, low density and the like, the aluminum-steel bimetal composite material is gradually more important in the fields of aviation, automobiles and the like, and the application is more and more extensive. At present, the main forming method of the aluminum-steel bimetal comprises the following steps: solid-liquid composite casting, diffusion bonding, extrusion and the like. The existing aluminum-steel bimetal solid-liquid composite casting technology utilizes a hot dipping method to soak steel in molten aluminum to form a layer of aluminum-steel bimetal interface at first, then the hot dipped steel is placed in a casting mold for casting molding, complete metallurgical bonding of the interface cannot be realized, certain gaps exist at the interface bonding position, the interface bonding strength is low, and the use requirements of people cannot be met.

The existing aluminum steel bimetal solid-liquid composite casting method has the following problems:

1. the hot dipping process is complicated;

2. the preheating temperature of a steel matrix is high, and the surface is easy to oxidize;

3. coarse aluminum side grains;

4. complete metallurgical bonding of the interface is not easy to realize;

5. the intermetallic compound at the interface is coarse and uneven in structure;

6. the interface bonding strength is low and the bonding performance is poor.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides a method for compositely casting aluminum steel solid-liquid bimetal, so as to improve the interface bonding strength of the aluminum steel solid-liquid bimetal and improve the comprehensive performance of the bimetal.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method for aluminum steel solid-liquid bimetal composite casting comprises the following steps:

a) smelting aluminum alloy into liquid, adding Al-5Ti-0.5C intermediate alloy into the liquid, and stirring for degassing; the content of the Al-5Ti-0.5C intermediate alloy is 4.5-5% of the weight of the aluminum alloy.

b) The aluminum alloy liquid after gas removal is put into a smelting furnace and heated to 708-710 ℃.

c) And (3) putting the preheated steel substrate into a sand mold, preheating a vibrator of an ultrasonic device, moving the preheated vibrator into the sand mold, and beginning to pour the aluminum alloy liquid.

d) After the pouring is finished, starting ultrasonic vibration; the frequency of ultrasonic vibration is 10KHz-20KHz, and the power is 1-3 KW; the time of ultrasonic vibration is 10-40 s.

Preferably, the preheating temperature of the steel matrix is 150-250 ℃; the heat preservation time of the steel matrix is 2-3 min.

Preferably, the aluminum alloy liquid is prepared by putting aluminum alloy into a crucible and smelting in a smelting furnace, wherein the smelting temperature is 750-800 ℃.

Preferably, Ar gas is used to degas the aluminum alloy melt.

Preferably, the aluminum alloy melt after degassing is cast after being heated to 710 ℃.

Preferably, the preheating temperature of the vibrator is 660-710 ℃, and the preheating time is 2-3 min.

More preferably, the preheating temperature of the vibrator is 700 ℃, and the preheating time is 2 min.

Preferably, the depth of the vibrator immersed into the aluminum alloy melt is 20 mm.

Preferably, the aluminum alloy material is ZL114A, and the steel matrix material is 45 steel.

Preferably, after the ultrasonic vibration is finished, the vibrator is moved out of the liquid level and cooled to room temperature, and the aluminum-steel bimetal composite material is obtained.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention uses the medium-frequency induction heating furnace to heat the steel matrix, so that the steel matrix is rapidly heated to the preset temperature before the aluminum alloy is poured, and the steel matrix is prevented from being oxidized due to long-time heating to block interface combination.

2. Al-5Ti-0.5C intermediate alloy is added to refine the aluminum alloy grains.

3. The cavitation effect of ultrasonic waves in the metal solution is utilized, an interface oxide film can be broken, the wetting of a steel matrix by molten metal is promoted, the interface reaction is facilitated, and the metallurgical bonding is formed. The function of dispersing Al-5Ti-0.5C intermediate alloy is achieved, so that the bimetal is better combined and the grains at the bimetal combination part are refined.

4. The acoustic streaming and cavitation effect of the ultrasonic waves generated in the metal solution can break up dendrites and help to disperse Al in the Al-5Ti-0.5C master alloy₃Ti and TiC, promote nucleation and form uniform and fine equiaxed grains.

5. And (3) breaking the intermetallic compounds at the interface by using the ultrasonic action.

6. The ultrasonic and Al-5Ti-0.5C can be used for obtaining an interface which is completely metallurgically bonded and has a fine structure at the bonding position, and the bonding strength at the solid-liquid interface of the aluminum steel is increased.

7. The aluminum-steel bimetal solid-liquid composite material prepared by casting by the method provided by the invention has the interface bonding strength of 60MPa, and is remarkably improved compared with the bonding strength of a similar product prepared by a traditional method, namely 20 MPa.

Drawings

FIG. 1 is a calculation chart of the stress simulation of a steel matrix under the ultrasonic action.

FIG. 2 is the calculation chart of sound pressure simulation inside the melt under the action of ultrasound.

FIG. 3 is a microscopic metallographic structure and scan of an article prepared according to the technique of the invention according to example 1.

FIG. 4 is a microscopic metallographic structure and scan of an article prepared according to example 2.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solution of the present invention is described in detail below with reference to the embodiments and the drawings, but the scope of protection is not limited thereto.

Example 1

1. And (5) manufacturing a casting sand mold.

2. Putting an aluminum alloy ingot into a crucible, and smelting in a smelting furnace at the smelting temperature of 750 ℃; the aluminum alloy material is ZL114A and one of aluminum-silicon alloys.

3. Preheating a steel substrate in a medium-frequency induction heating furnace at 200 ℃; the base material of the steel is 45 steel.

4. Putting Al-5Ti-0.5C intermediate alloy into the aluminum alloy melt, stirring, and degassing the aluminum alloy melt by using Ar gas; the content of the Al-5Ti-0.5C intermediate alloy is 5 percent of the weight of the aluminum alloy ingot.

5. And (3) putting the vibrator into the aluminum alloy melt for preheating, wherein the preheating temperature is 700 ℃, and the preheating time is 2 min.

6. And putting the preheated and heat-insulated steel matrix into the center of the sand mold.

7. After the preheating of the vibrator is finished, the vibrator is moved into a sand mold, the temperature of the aluminum alloy melt after the previous treatment is raised to 710 ℃, then the aluminum alloy melt is poured, and the immersion depth of the vibrator is 20 mm.

8. After the pouring is finished, starting ultrasonic vibration; the frequency is 20KHz, and the power is 1 KW; the vibration time was 30 s.

9. And (4) closing the ultrasonic vibration, moving the vibrator out of the liquid level, and cooling to room temperature to obtain the aluminum-steel bimetal composite material. The bonding strength of the aluminum-steel bimetal composite material is 55 MPa.

Example 2

1. And (5) manufacturing a casting sand mold.

2. Putting an aluminum alloy ingot into a crucible, and smelting in a smelting furnace at the smelting temperature of 780 ℃; the aluminum alloy material is ZL114A and one of aluminum-silicon alloys.

3. Preheating a steel substrate in a medium-frequency induction heating furnace at 250 ℃; the base material of the steel is 45 steel.

4. Putting Al-5Ti-0.5C intermediate alloy into the aluminum alloy melt, stirring, and degassing the aluminum alloy melt by using Ar gas; the content of the Al-5Ti-0.5C intermediate alloy is 5 percent of the weight of the aluminum alloy ingot.

5. And (3) putting the vibrator into the aluminum alloy melt for preheating, wherein the preheating temperature is 710 ℃, and the preheating time is 3 min.

6. And putting the preheated and heat-insulated steel matrix into the center of the sand mold.

7. After the preheating of the vibrator is finished, the vibrator is moved into a sand mold, the temperature of the aluminum alloy melt after the previous treatment is raised to 710 ℃, then the aluminum alloy melt is poured, and the immersion depth of the vibrator is 20 mm.

8. After the pouring is finished, starting ultrasonic vibration; the frequency is 15KHz, and the power is 2 KW; the vibration time was 30 s.

9. And (4) closing the ultrasonic vibration, moving the vibrator out of the liquid level, and cooling to room temperature to obtain the aluminum-steel bimetal composite material. The bonding strength of the aluminum-steel bimetal composite material is 60 MPa.

While the invention has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.