An aluminum-based alloy material, a preparation method and application thereof

Abstract

The application belongs to the technical field of transient liquid-phase diffusion welding, and particularly relates to an aluminum-based alloy material and a preparation method and application thereof. The aluminum-based alloy material provided by the application comprises the following chemical components in percentage by mass: 6.5-7.5% of Si, 19.5-20.5% of Cu, 2.5-3.5% of Mg, 0.5-1.5% of Ni, 2.5-3.5% of Zn, 0.5-1.5% of Ga, 0.1-0.2% of Ce, and the balance of Al. Silicon and copper are used as melting elements, and magnesium is used to assist in breaking the oxide film. Silicon and copper form low-melting eutectic liquid phase with the base material; the chemical activity of magnesium is greater than that of aluminum, and under the heating condition, magnesium can reduce the dense aluminum oxide film on the surface of the aluminum alloy into a low-melting-point oxide which is melted into the eutectic liquid phase in the welding process, so that the effect of breaking the oxide film is achieved; the mutual diffusion of gallium and aluminum can further inhibit the formation of the oxide film on the surface of the aluminum alloy, thereby improving the welding effect.

Description

Technical Field

[0001] This invention belongs to the field of instantaneous liquid phase diffusion welding technology, specifically relating to an aluminum-based alloy material, its preparation method, and its application. Background Technology

[0002] Transient liquidphase bonding (TLP) utilizes the self-melting of the interlayer or its eutectic reaction with the base material to obtain a certain amount of liquid phase at the bonding interface. This liquid phase also acts as a diffusion bridge, accelerating diffusion. Melting point depressants (MPD) in the liquid phase rapidly diffuse into the matrix, significantly altering the chemical composition of the bonding interface. This leads to isothermal solidification of the bonding interface after holding at a certain temperature for a period of time. Through isothermal solidification and homogenization of the solid phase composition, a welded joint with a uniform chemical composition and microstructure consistent with the base material and a continuous bonding surface microstructure is obtained. The composition of the interlayer material is crucial for obtaining a high-quality joint; currently, copper foil or nickel-based amorphous metal foil are most commonly used as interlayer materials in transient liquidphase bonding.

[0003] However, when using existing intermediate layer materials for instantaneous liquid phase diffusion welding of aluminum alloy substrates, the dense oxide film on the surface of the aluminum alloy base material severely hinders good contact between the intermediate layer and the base metal, thereby reducing the quality of the weld joint. Summary of the Invention

[0004] In view of this, the present invention provides an aluminum-based alloy material, its preparation method and application. When the aluminum-based alloy material provided by the present invention is used as an intermediate layer material to perform instantaneous liquid phase diffusion welding on an aluminum alloy substrate, the oxide film on the surface of the aluminum alloy can be broken, thereby improving the welding effect of instantaneous liquid phase diffusion welding.

[0005] To address the aforementioned technical problems, this invention provides an aluminum-based alloy material comprising the following chemical components in weight percentage:

[0006]

[0007]

[0008] Preferably, the chemical components include the following chemical components in weight percentages:

[0009]

[0010] The present invention also provides a method for preparing the aluminum-based alloy material described in the above technical solution, comprising the following steps:

[0011] The raw materials are mixed and smelted according to the element group ratio to obtain a molten liquid;

[0012] The molten liquid is poured into a container to obtain the aluminum-based alloy material.

[0013] Preferably, the melting temperature is 830–850°C and the melting time is 20–40 min.

[0014] Preferably, the casting temperature is 730–750°C.

[0015] Preferably, the raw materials include aluminum-silicon master alloy, aluminum-copper master alloy, aluminum-magnesium master alloy, aluminum-nickel master alloy, aluminum-cerium master alloy, zinc, gallium, and aluminum.

[0016] Preferably, the silicon content in the aluminum-silicon master alloy is 18-22% by mass, the copper content in the aluminum-copper master alloy is 48-52% by mass, the magnesium content in the aluminum-magnesium master alloy is 48-52% by mass, the nickel content in the aluminum-nickel master alloy is 8-12% by mass, and the cerium content in the aluminum-cerium master alloy is 8-12% by mass.

[0017] The present invention also provides the application of the aluminum-based alloy material described in the above technical solution or the aluminum-based alloy material prepared by the preparation method described in the above technical solution as an intermediate layer material for instantaneous liquid phase diffusion welding.

[0018] Preferably, the base material for the instantaneous liquid phase diffusion welding is an aluminum alloy.

[0019] Preferably, the aluminum-based alloy material is in sheet form when used as an intermediate layer material in instantaneous liquid phase diffusion welding.

[0020] This invention provides an aluminum-based alloy material comprising the following chemical components by mass percentage: 6.5–7.5% Si, 19.5–20.5% Cu, 2.5–3.5% Mg, 0.5–1.5% Ni, 2.5–3.5% Zn, 0.5–1.5% Ga, 0.1–0.2% Ce, and the balance Al. This invention uses silicon and copper as melting-reducing elements, and incorporates magnesium to assist in breaking down the oxide film. In this invention, silicon and copper form a low-melting-point eutectic liquid phase with the base material; simultaneously, Mg has greater chemical reactivity than Al, and under heating conditions, Mg can reduce the dense alumina film on the aluminum alloy surface to a low-melting-point oxide (MgAl₂O₄), which melts into the eutectic liquid phase during welding, thereby achieving the effect of breaking down the oxide film; furthermore, the interdiffusion of Ga and Al can further inhibit the formation of an oxide film on the aluminum alloy surface, thereby improving the welding effect of instantaneous liquid phase diffusion welding. When the aluminum-based alloy material provided by this invention is used as the intermediate layer material for instantaneous liquid phase diffusion welding with aluminum alloy as the base material, it can break the oxide film on the surface of the aluminum alloy and improve the welding effect of instantaneous liquid phase diffusion welding. Attached Figure Description

[0021] Figure 1 The following are DSC curves of the aluminum-based alloy materials in Examples 1-3 and Comparative Example 1;

[0022] Figure 2 This is an illustration of the wetting and spreading of aluminum-based alloy materials in Examples 1-3 and Comparative Example 1 on the surface of 5A06 aluminum alloy base material.

[0023] Figure 3 The images show the wetting interface morphology of the aluminum-based alloy materials and 5A06 aluminum alloy base material in Examples 1-3 and Comparative Example 1. Detailed Implementation

[0024] This invention provides an aluminum-based alloy material comprising the following chemical components in weight percentage:

[0025]

[0026] The aluminum-based alloy material provided by the present invention comprises 6.5 to 7.5% Si, preferably 6.94 to 7.0%, by mass percentage.

[0027] The aluminum-based alloy material provided by the present invention comprises 19.5-20.5% Cu, preferably 19.89-20.0%, by mass percentage.

[0028] The aluminum-based alloy material provided by the present invention comprises 2.5 to 3.5% Mg, preferably 3.0 to 3.02%, by mass percentage.

[0029] The aluminum-based alloy material provided by the present invention comprises 0.5 to 1.5% Ni, preferably 1.0 to 1.02%, by mass percentage.

[0030] The aluminum-based alloy material provided by the present invention comprises 2.5 to 3.5% Zn, preferably 3.0 to 3.05% by mass percentage.

[0031] The aluminum-based alloy material provided by the present invention comprises 0.5 to 1.5% Ga, preferably 1.0 to 1.35%, by mass percentage.

[0032] The aluminum-based alloy material provided by the present invention comprises 0.1-0.2% Ce, preferably 0.15-0.16%, by mass percentage.

[0033] The aluminum-based alloy material provided by this invention comprises the balance Al by weight percentage.

[0034] In this invention, both Si and Cu can undergo a low-melting eutectic reaction with Al, and a ternary eutectic reaction exists between Al-Si-Cu. The eutectic temperature of 525°C can effectively reduce the melting point of the intermediate layer alloy. At the same time, Si can effectively improve the fluidity of the aluminum alloy and promote the wetting and spreading of the intermediate layer on the surface of the base material.

[0035] In this invention, when Cu is added in excess, it will form a large amount of brittle intermetallic compound Al2Cu with Al, which will seriously damage the joint performance. This invention can effectively alleviate the generation of brittle phase by replacing Cu with a small amount of Ni in the aluminum alloy, while improving the joint strength and corrosion resistance.

[0036] In this invention, Mg is more chemically reactive than Al. Under heating conditions, Mg can reduce the dense Al2O3 on the surface of aluminum alloy into low-melting-point oxides, which melt into the intermediate layer during the welding process, thereby achieving the effect of breaking the oxide film. At the same time, the mutual diffusion between Ga and Al can further inhibit the formation of oxide film on the surface of aluminum alloy and improve the welding quality.

[0037] In this invention, Zn, as the main strengthening element, works in conjunction with Mg to form the MgZn2 strengthening phase, thereby achieving joint strengthening.

[0038] In this invention, trace amounts of rare earth element Ce are used as a modifier to improve the microstructure of the joint, refine the grains, and further improve the mechanical properties of the welded joint.

[0039] The aluminum-based alloy material provided by this invention uses aluminum as the basic element and incorporates a certain amount of melting-reducing elements, film-breaking elements, and strengthening elements, which can obtain aluminum alloy TLP diffusion welded joints with uniform structure and continuous composition.

[0040] The preferred melting temperature of the aluminum-based alloy material provided by the present invention is 492.48 to 527.48°C, and the aluminum-based alloy material provided by the present invention can be subjected to TLP diffusion welding at temperatures above 530°C.

[0041] The present invention also provides a method for preparing the aluminum-based alloy material described in the above technical solution, comprising the following steps:

[0042] The raw materials are mixed and smelted according to the element group ratio to obtain a molten liquid;

[0043] The molten liquid is poured into a container to obtain the aluminum-based alloy material.

[0044] This invention involves mixing and melting raw materials according to an elemental composition ratio to obtain a molten liquid. In this invention, the raw materials preferably include aluminum-silicon master alloys, aluminum-copper master alloys, aluminum-magnesium master alloys, aluminum-nickel master alloys, aluminum-cerium master alloys, zinc, gallium, and aluminum. In this invention, the mass percentage of silicon in the aluminum-silicon master alloy is preferably 18-22%, more preferably 20%; the mass percentage of copper in the aluminum-copper master alloy is preferably 48-52%, more preferably 50%; the mass percentage of magnesium in the aluminum-magnesium master alloy is preferably 48-52%, more preferably 50%; the mass percentage of nickel in the aluminum-nickel master alloy is preferably 8-12%, more preferably 10%; and the mass percentage of cerium in the aluminum-cerium master alloy is preferably 8-12%, more preferably 10%. In this invention, the purity of zinc is preferably 99.99% or higher; the purity of gallium is preferably 99.99% or higher; and the purity of aluminum is preferably 99.99% or higher.

[0045] In this invention, the melting temperature is preferably 830–850°C, more preferably 840–845°C. In this invention, the melting is preferably carried out in a microwave melting furnace.

[0046] In this invention, the melting is preferably carried out in a vacuum melting and non-vacuum melting manner in sequence. Specifically, the Al-Si master alloy, Al-Cu master alloy, Al-Ni master alloy and aluminum non-volatile materials are vacuum melted to obtain a partial melt; the Al-Mg master alloy with high vapor pressure, zinc, Al-Ce master alloy and gallium are wrapped in aluminum foil and pressed into a portion of the melt for non-vacuum melting.

[0047] In this invention, the vacuum degree of the vacuum melting is preferably 4 × 10⁻⁶. -2 ~8×10 -3 Pa, more preferably 1×10 Pa -3 ~8×10 -3 Pa. In this invention, the vacuum melting time is preferably 20-40 min, more preferably 20-35 min. In this invention, the non-vacuum melting time is preferably 20-40 min, more preferably 20-35 min. In this invention, a covering agent is preferably added during the non-vacuum melting process; the covering agent is preferably a mixture of KCl and NaCl, the mass ratio of KCl to NaCl is preferably 1:1, and the amount of covering agent added is preferably 10% of the melt mass. In this invention, the non-vacuum melting is preferably accompanied by stirring; this invention has no special requirements for the stirring, as long as uniform melting is achieved.

[0048] After obtaining the molten liquid, the present invention casts the molten liquid to obtain the aluminum-based alloy material. In the present invention, the casting temperature is preferably 730-750°C, more preferably 740-745°C. The present invention has no special requirements for the casting process, and conventional methods in the art can be used.

[0049] This invention also provides the application of the aluminum-based alloy material described in the above-described technical solutions or the aluminum-based alloy material prepared by the preparation method described in the above-described technical solutions as an intermediate layer material for instantaneous liquid phase diffusion welding. In this invention, the base material for instantaneous liquid phase diffusion welding is preferably 5A06 aluminum alloy. In this invention, the aluminum-based alloy material is preferably in sheet form when used as an intermediate layer material for instantaneous liquid phase diffusion welding.

[0050] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0051] In the embodiments of the present invention, Al-20Si master alloy is an aluminum-silicon master alloy with a silicon mass percentage of 20%, Al-50Cu master alloy is an aluminum-copper master alloy with a copper mass percentage of 50%, Al-50Mg master alloy is an aluminum-magnesium master alloy with a magnesium mass percentage of 50%, Al-10Ni master alloy is an aluminum-nickel master alloy with a nickel mass percentage of 10%, and Al-10Ce master alloy is an aluminum-cerium master alloy with a cerium mass percentage of 10%.

[0052] Example 1

[0053] Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, and aluminum (purity 99.99 wt.%) were placed in a microwave melting furnace and melted at a temperature of 830℃ and a vacuum degree of 4×10⁻⁶. -2 Vacuum melting was carried out for 20 minutes under Pa conditions to obtain a partial melt.

[0054] Al-50Mg master alloy, Al-10Ce master alloy, zinc (purity 99.99 wt.%), and gallium (purity 99.99 wt.%) were wrapped in aluminum foil and pressed into a portion of the molten metal. The mixture was stirred until completely melted, and a covering agent (a mixture of KCl and NaCl in a 1:1 mass ratio) was added. The mixture was then smelted in a non-vacuum environment for 20 minutes to obtain the molten metal. The amount of covering agent was 10% of the total mass of Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, aluminum, Al-50Mg master alloy, Al-10Ce master alloy, zinc, and gallium.

[0055] The molten metal is cooled to 730°C and then cast to obtain an aluminum-based alloy material. The aluminum-based alloy material comprises the following components by mass percentage: Si 6.5%, Cu 19.5%, Mg 2.5%, Ni 0.5%, Zn 2.5%, Ga 0.5%, Ce 0.1%, and the balance Al.

[0056] Example 2

[0057] Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, and aluminum (purity 99.99 wt.%) were placed in a microwave melting furnace at a temperature of 840℃ and a vacuum degree of 1×10⁻⁶. -3 Vacuum melting was carried out for 30 minutes under Pa conditions to obtain a partial melt.

[0058] Al-50Mg master alloy, Al-10Ce master alloy, zinc (99.99 wt.% purity), and gallium (99.99 wt.% purity) were wrapped in aluminum foil and pressed into a portion of the molten metal. The mixture was stirred until completely melted, and a covering agent (a mixture of KCl and NaCl in a 1:1 mass ratio) was added. The mixture was then smelted in a non-vacuum environment for 30 minutes to obtain the molten metal. The amount of covering agent was 10% of the total mass of Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, aluminum, Al-50Mg master alloy, Al-10Ce master alloy, zinc, and gallium.

[0059] The molten metal is cooled to 740°C and then cast to obtain an aluminum-based alloy material. The aluminum-based alloy material comprises the following components by mass percentage: Si 7.0%, Cu 20.0%, Mg 3.0%, Ni 1.0%, Zn 3.0%, Ga 1.0%, Ce 0.15%, and the balance Al.

[0060] Example 3

[0061] Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, and aluminum (purity 99.99 wt.%) were placed in a microwave melting furnace and melted at a temperature of 850℃ and a vacuum degree of 8×10⁻⁶. -3 Vacuum melting was carried out under Pa conditions for 40 minutes to obtain a partial melt.

[0062] Al-50Mg master alloy, Al-10Ce master alloy, zinc (99.99 wt.% purity), and gallium (99.99 wt.% purity) were wrapped in aluminum foil and pressed into a portion of the molten metal. The mixture was stirred until completely melted, and a covering agent (a mixture of KCl and NaCl in a 1:1 mass ratio) was added. The mixture was then smelted in a non-vacuum environment for 40 minutes to obtain the molten metal. The amount of covering agent was 10% of the total mass of Al-20Si master alloy, Al-50Cu master alloy, Al-10Ni master alloy, aluminum, Al-50Mg master alloy, Al-10Ce master alloy, zinc, and gallium.

[0063] The molten metal is cooled to 750°C and then cast to obtain an aluminum-based alloy material. The aluminum-based alloy material comprises the following components by mass percentage: Si 7.5%, Cu 20.5%, Mg 3.5%, Ni 1.5%, Zn 3.5%, Ga 1.5%, Ce 0.2%, and the balance Al.

[0064] Comparative Example 1

[0065] Al-12Si solder was used as a comparative example, where Al-12Si solder is an aluminum-silicon alloy with a silicon mass percentage of 12%.

[0066] The solid and liquidus lines of the aluminum-based alloy materials in Examples 1-3 and Comparative Example 1 were tested using differential scanning calorimetry (DSC). The resulting DSC curves are shown below. Figure 1 As shown; the temperatures of the obtained solidus and liquidus are listed in Table 1.

[0067] Table 1. DSC test results of aluminum-based alloy materials in Examples 1-3 and Comparative Example 1

[0068] Example Solidus line / ℃ Liquidus / ℃ Example 1 492.48 527.48 Example 2 490.68 527.42 Example 3 497.13 528.54 Comparative Example 1 577 581

[0069] Combination Figure 1 As can be seen from the results in Table 1, the melting point of the aluminum-based alloy materials prepared in Examples 1-3 is significantly lower than that of commercially available aluminum-silicon eutectic brazing fillers, and they have a wider range of applications.

[0070] The wetting angle of the aluminum-based alloy materials prepared in Examples 1-3 on the surface of 5A06 aluminum alloy was measured using the contact angle method. The test results are shown in Table 2. Figure 2 The images show the wetting and spreading of the aluminum-based alloy materials of Examples 1-3 and Comparative Example 1 on the surface of 5A06 aluminum alloy base material. Figure 3 The images show the wetting interface morphology of the aluminum-based alloy materials and 5A06 aluminum alloy base material in Examples 1-3 and Comparative Example 1.

[0071] Table 2. Wetting angles of aluminum-based alloy materials in Examples 1-3 and Comparative Example 1 on the surface of 5A06 aluminum alloy.

[0072] Example Wetting angle / ° Example 1 30.5 Example 2 29.1 Example 3 26.2 Comparative Example 1 143.6

[0073] Combination Figure 2 As can be seen from Table 2, the aluminum-based alloy materials prepared in Examples 1-3 can all wet the aluminum alloy surface under non-vacuum conditions, while the Al-12Si solder in Comparative Example 1 cannot wet the aluminum alloy surface. Furthermore, combined with... Figure 3 The reaction interface between the intermediate layer and the 5A06 base material shows that after melting in Examples 1-3, the intermediate layer reacts with the base material and causes local dissolution of the base material. At the same time, the oxide film on the surface of the base material melts into the liquid phase, which plays a role in breaking the oxide film. However, the brazing filler metal used in the comparative example cannot wet and spread on the surface of the base material in a non-vacuum environment due to the presence of the oxide film on the surface of the base material.

[0074] Using the aluminum-based alloy materials obtained in Examples 1-3 and Comparative Example 1 as intermediate layer materials, instantaneous liquid phase diffusion welding tests were conducted on 5A06 aluminum alloy under the condition of holding at 570℃ for 30 min. The tensile strength of the welded joint was tested using a universal testing machine. The test results are shown in Table 3.

[0075] Table 35A06 Aluminum Alloy Instantaneous Liquid Phase Diffusion Welded Joint Tensile Strength

[0076] Intermediate layer material Tensile strength / MPa Example 1 182.53 Example 2 189.32 Example 3 219.17 Comparative Example 1 110.59

[0077] As can be seen from Table 3, the welded joints obtained by instantaneous liquid phase diffusion welding of aluminum alloys using the aluminum-based alloy materials prepared in Examples 1-3 as intermediate layer materials have high tensile strength and improve welding quality.

[0078] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An aluminum-based alloy material, characterized in that, The chemical components include the following components by mass percentage: Si 6.5~7.5%; Cu 19.5~20.5%; Mg 2.5~3.5%; Ni 0.5~1.5%; Zn 2.5~3.5%; Ga 0.5~1.5%; Ce 0.1~0.2%; Al balance; The method for preparing the aluminum-based alloy material includes the following steps: The raw materials are mixed and smelted according to the elemental composition ratio to obtain a molten liquid; the smelting temperature is 830~850℃. The molten metal is poured into the aluminum-based alloy material to obtain the aluminum alloy material; the pouring temperature is 730~750℃.

2. The aluminum-based alloy material according to claim 1, characterized in that, The chemical components include the following components by mass percentage: Si 6.94~7.0%; Cu 19.89~20.0%; Mg 3.0~3.02%; Ni 1.0~1.02%; Zn 3.0~3.05%; Ga 1.0~1.35%; Ce 0.15~0.16%; Al represents the remaining amount.

3. A method for preparing the aluminum-based alloy material according to claim 1 or 2, comprising the following steps: The raw materials are mixed and smelted according to the elemental composition ratio to obtain a molten liquid; the smelting temperature is 830~850℃. The molten metal is poured into the aluminum-based alloy material to obtain the aluminum alloy material; the pouring temperature is 730~750℃.

4. The preparation method according to claim 3, characterized in that, The melting time is 20-40 minutes.

5. The preparation method according to claim 3, characterized in that, The raw materials include aluminum-silicon master alloy, aluminum-copper master alloy, aluminum-magnesium master alloy, aluminum-nickel master alloy, aluminum-cerium master alloy, zinc, gallium, and aluminum.

6. The preparation method according to claim 5, characterized in that, The aluminum-silicon master alloy contains 18-22% silicon by mass, the aluminum-copper master alloy contains 48-52% copper by mass, the aluminum-magnesium master alloy contains 48-52% magnesium by mass, the aluminum-nickel master alloy contains 8-12% nickel by mass, and the aluminum-cerium master alloy contains 8-12% cerium by mass.

7. The application of the aluminum-based alloy material according to claim 1 or 2 or the aluminum-based alloy material prepared by the preparation method according to any one of claims 3 to 6 as an intermediate layer material for instantaneous liquid phase diffusion welding.

8. The application according to claim 7, characterized in that, The base material for the instantaneous liquid phase diffusion welding is aluminum alloy.

9. The application according to claim 7 or 8, characterized in that, The aluminum-based alloy material is in sheet form when used as an intermediate layer material in instantaneous liquid phase diffusion welding.

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