A method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer

Abstract

The application discloses a laser additive connection method for aluminum alloy-titanium alloy components with high-entropy alloy as an intermediate layer, and belongs to the technical field of laser additive manufacturing. The connection method comprises the following steps: preparing a V-shaped groove for aluminum alloy components and titanium alloy components to be connected through mechanical processing; and preparing a high-entropy alloy intermediate layer at the V-shaped groove through a laser additive manufacturing process by using TiNbVZr or TiNbV high-entropy alloy powder to connect the aluminum alloy components and the titanium alloy components. The application prepares the high-entropy alloy with two optimal components into the intermediate layer of the aluminum alloy-titanium alloy components through the laser additive manufacturing method, avoids the generation and cracking of intermetallic compounds in the process of directly connecting the aluminum alloy-titanium alloy through the laser, and further significantly improves the bonding strength of the connection area of the aluminum alloy-titanium alloy components.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser additive manufacturing, and particularly relates to a laser additive connection method for aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer. BACKGROUND

[0002] Titanium alloy has the advantages of low density, high specific strength and good corrosion resistance, aluminum alloy has the advantages of low price, low density and high specific strength, and aluminum alloy components and titanium alloy components are widely used in the fields of aviation, aerospace and automobiles, and therefore a large number of aluminum alloy-titanium alloy component connections are needed in the field of industrial manufacturing.

[0003] At present, the manufacturing of aluminum alloy-titanium alloy component connections is mainly realized by traditional welding methods, including diffusion welding, ultrasonic welding, arc fusion brazing and the like, and the typical disadvantage of the methods is that the bonding strength of the welding connection area is low, and the tensile strength is generally only 10-30 MPa. Due to the significant physical and chemical differences between aluminum alloy and titanium alloy, welding of aluminum / titanium dissimilar structures is difficult, a large number of brittle intermetallic compounds are generated at the interface of the dissimilar alloy, and traditional laser / electron beam melting welding technology cannot be applied, which greatly limits the application of aluminum alloy-titanium alloy component connections.

[0004] High-entropy alloy can make Al and Ti elements tend to form a solid solution rather than precipitate intermetallic compounds due to its high mixing entropy, slow diffusion rate and high stability, and can also alleviate the physical property difference between aluminum alloy and titanium alloy, thereby becoming a candidate material for the intermediate layer of aluminum alloy-titanium alloy connection. The use of laser additive manufacturing technology to prepare a high-entropy alloy intermediate layer to realize aluminum alloy-titanium alloy component connection can avoid the generation of TiAl-based brittle intermetallic compounds in the connection area and the cracking of the connection area interface, thereby preparing a high-performance aluminum alloy-titanium alloy component connection. At the same time, there are many composition systems of high-entropy alloy, and it is necessary to find a high-entropy alloy system that can simultaneously dissolve a high content of Al and Ti in order to achieve good connection effect. SUMMARY

[0005] The application aims to provide a laser additive connection method for aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer. The high-entropy alloy with two optimal compositions is prepared into an intermediate layer of aluminum alloy-titanium alloy components by laser additive manufacturing, which avoids the generation and cracking of intermetallic compounds in the process of direct laser connection of aluminum alloy and titanium alloy, and thereby significantly improves the bonding strength of the connection area of aluminum alloy-titanium alloy components.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] A method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer, comprising the following steps:

[0008] The aluminum alloy component and the titanium alloy component to be connected are prepared into a V-shaped groove by mechanical processing; a high-entropy alloy intermediate layer is prepared at the V-shaped groove by using TiNbVZr or TiNbV high-entropy alloy powder through a laser additive manufacturing process to connect the aluminum alloy component and the titanium alloy component.

[0009] Preferably, the material of the aluminum alloy component includes but is not limited to common aluminum alloy brands such as ZL105A, AlSi10Mg, 5A06, 2024, 6061, 5083, 6061, 7075, etc.

[0010] Preferably, the material of the titanium alloy component includes but is not limited to common titanium alloy brands such as TA2, TA15, TC4, TC11, TC21, TC18, etc.

[0011] Preferably, the grooves of the aluminum alloy component and the titanium alloy component are pretreated before laser additive manufacturing.

[0012] Preferably, the groove slope of the groove of the aluminum alloy component forms an angle of 30-60° with the horizontal direction; the groove slope of the groove of the titanium alloy component forms an angle of 30-60° with the horizontal direction.

[0013] Preferably, the atomic ratio of Ti, Nb, V and Zr in the TiNbVZr high-entropy alloy powder is 1:0.5-2:0.5-2:0.5-2, and the powder particle size range is 53-250μm; the atomic ratio of Ti, Nb and V in the TiNbV high-entropy alloy powder is 1:0.5-2:0.5-2, and the powder particle size range is 53-250μm.

[0014] More preferably, the TiNbVZr high-entropy alloy powder and the TiNbV high-entropy alloy powder are subjected to a drying treatment of 120℃ for 2h before use.

[0015] Preferably, the process parameters of the laser additive manufacturing process are: laser beam diameter 3-6mm, laser power 2-6KW, scanning speed 500-1500mm / min, single layer height 0.3-0.6mm, overlap rate 30-50%, powder feeding rate 800-2000g / h, oxygen content less than 80ppm.

[0016] Preferably, after the high-entropy alloy intermediate layer is prepared, an annealing treatment step is further included.

[0017] More preferably, the annealing treatment temperature is 200-500℃, the holding time is 1-6h, and the cooling method is air cooling or furnace cooling.

[0018] The beneficial technical effects of the present application are as follows:

[0019] The application provides an aluminum alloy-titanium alloy component laser additive connection method using high-entropy alloy as an intermediate layer. The provided method first uses TiNbVZr or TiNbV high-entropy alloy as a filling material of an aluminum alloy-titanium alloy component connection area. The TiNbVZr or TiNbV high-entropy alloy intermediate layer prepared by a laser additive manufacturing process avoids the generation and cracking of TiAl brittle intermetallic compounds in the process of directly additive connection of aluminum alloy and titanium alloy, and can prepare an aluminum alloy-titanium alloy component with relatively high bonding strength. The successful preparation of the aluminum / high-entropy alloy / titanium alloy gradient material can provide a new preparation idea for the laser additive connection of titanium / steel, nickel / steel, titanium / nickel and other dissimilar metals, and can be implemented in related fields. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic diagram of aluminum alloy components and titanium alloy components with V-shaped grooves after machining.

[0021] Figure 2 A schematic diagram of a high-entropy alloy intermediate layer for connecting aluminum alloy components and titanium alloy components with V-shaped grooves by using a laser additive manufacturing process.

[0022] Figure 3 A schematic diagram of aluminum alloy components and titanium alloy components with V-shaped grooves connected by a high-entropy alloy intermediate layer.

[0023] Among them, 1-aluminum alloy component; 2-titanium alloy component; 3-laser additive manufacturing equipment; 4-laser beam; 5-workbench; 6-laser additive manufacturing high-entropy alloy intermediate layer connection area. DETAILED DESCRIPTION

[0024] The various illustrative embodiments of the present application will now be described in detail in connection with the following figures. This description is not to be taken in a limiting sense but is made merely for the purpose of providing a full and enabling disclosure of the application. The best mode contemplated for carrying out the present application is illustrated in the detailed description and accompanying drawings.

[0025] In addition, for numerical ranges in the present application, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value between any stated value or stated range, as well as any other stated value or intermediate value in the stated range, is also included within the present application. The upper and lower limits of these smaller ranges can be independently included or excluded from the ranges.

[0026] Unless otherwise indicated, all technical and scientific terms have the same meaning as those one of ordinary skill in the art of the application would understand. Although preferred methods and materials are described, any method and material similar or equivalent to those described herein can be used in the practice or testing of the present application.

[0027] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean including, but not limited to.

[0028] The schematic diagram of the aluminum alloy member and the titanium alloy member with V-shaped groove prepared by mechanical processing in the embodiment of the present application is shown in Figure 1 ; the schematic diagram of the high-entropy alloy intermediate layer connecting the aluminum alloy member and the titanium alloy member with V-shaped groove prepared by laser additive manufacturing process is shown in Figure 2 ; the schematic diagram of the aluminum alloy member and the titanium alloy member with V-shaped groove after being connected by the high-entropy alloy intermediate layer is shown in Figure 3 .

[0029] In the figure, 1 is an aluminum alloy member; 2 is a titanium alloy member; 3 is a laser additive manufacturing device; 4 is a laser beam; 5 is a workbench; 6 is a laser additive manufacturing high-entropy alloy intermediate layer connecting area.

[0030] The high-entropy alloy intermediate layer in the embodiment of the present application is manufactured by an LMD-V laser forming manufacturing system. The specific operation of the system is as follows: the aluminum alloy member and the titanium alloy member with machined groove are fixed on the workbench 5 of the LMD-V laser additive manufacturing device shown in Figure 2 ; the high-entropy alloy powder is used as the intermediate layer material of the laser additive connecting area, the high-entropy alloy powder is a pre-alloy powder, the powder particle size is 53-250 μm, and the entire laser additive connecting preparation process is carried out in an inert gas protection atmosphere.

[0031] Example 1

[0032] The steps of connecting the ZL105A aluminum alloy member and the TC11 titanium alloy member by the TiNbVZr high-entropy alloy intermediate layer are as follows:

[0033] S1, prepare high-entropy alloy powder, aluminum alloy and titanium alloy workpieces to be connected: the high-entropy alloy powder has a composition of TiNbVZr (equal atomic ratio) and a particle size of 75-250 μm; the aluminum alloy member to be connected has a grade of ZL105A (nominal composition Al-5Si-1Cu-Mg), and the titanium alloy member to be connected has a grade of TC11 (nominal chemical composition Ti-6.5Al-3.5Mo-1.5Zr-0.3Si).

[0034] S2, the TiNbVZr high-entropy alloy powder is pretreated: it is placed in a vacuum oven for drying treatment, the drying conditions are 120°C for 2h, to remove moisture and increase the flowability of the powder during forming.

[0035] S3, the aluminum alloy component and the titanium alloy component to be connected are prepared by mechanical processing to have a 45° bevel, and the component has an outer dimension of 60mm x 40mm x 20mm. The two bevels and the surrounding areas are polished with sandpaper until the metal luster is exposed, and then cleaned with alcohol to remove surface oil stains.

[0036] S4, according to the size of the bevel of the TC11 titanium alloy and the ZL105A component to be connected, the scanning path of the intermediate high-entropy alloy connecting zone is set. The laser additive manufacturing process file is written and imported into the control system of the equipment. The process parameters for depositing the intermediate high-entropy alloy layer are as follows: laser beam diameter is 6mm, laser power is 3.5KW, scanning speed is 1000mm / min, single layer lifting height is 0.5mm, powder feeding rate is 1000g / h, and overlap rate is 40%.

[0037] S4, the TC11 titanium alloy and the component to be connected of ZL105A are fixed on the machine tool workbench, and inert gas Ar is introduced to maintain the oxygen content in the entire forming environment below 80ppm.

[0038] S5, after the laser additive connection of the TC11 titanium alloy and the ZL105A aluminum alloy is completed, the laser additive connection sample is placed in a heat treatment furnace for overall stress relief annealing heat treatment, the annealing temperature is 200°C, the holding time is 2h, and the furnace is cooled.

[0039] Example 2

[0040] The steps of connecting the ZL105A aluminum alloy component and the TC11 titanium alloy component by the TiNbV high-entropy alloy intermediate layer are as follows:

[0041] Compared with Example 1, the only difference is that the equiatomic TiNbV high-entropy alloy powder (powder particle size is 75-250μm) is used to replace the equiatomic TiNbVZr high-entropy alloy powder.

[0042] The tensile properties of the materials obtained after the aluminum alloy component and the titanium alloy component are connected by the high-entropy alloy intermediate layer in Examples 1-2 are tested, and the test results are shown in Table 1.

[0043] Table 1 Tensile properties of aluminum alloy component and titanium alloy component connected by high-entropy alloy intermediate layer

[0044]

[0045] It can be concluded from the results of Table 1 that the connecting zones of the aluminum alloy component and the titanium alloy component are prepared by using the TiNbVZr or TiNbV high-entropy alloy powder through the laser additive manufacturing process, and the tensile strength of the connecting zones is 104 MPa and 116 MPa respectively through testing, and the tensile performance is excellent. The aluminum alloy-titanium alloy component laser additive connection technology using high-entropy alloy as an intermediate layer provided in the application can meet the manufacturing requirements of the aluminum alloy component and the titanium alloy component welding / connection in the industrial manufacturing field, and provides a new preparation idea for the connection of other high-performance dissimilar metals.

[0046] The above-described embodiments are only used to describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an interlayer, characterized in that, The method comprises the following steps: The aluminum alloy component and the titanium alloy component to be connected are prepared into V-shaped grooves by mechanical processing; A high-entropy alloy intermediate layer is prepared at the V-shaped groove by using TiNbVZr or TiNbV high-entropy alloy powder through a laser additive manufacturing process to connect the aluminum alloy component and the titanium alloy component; The atomic ratio of Ti, Nb, V and Zr in the TiNbVZr high-entropy alloy powder is 1:0.5-2:0.5-2:0.5-2, and the powder particle size range is 53-250 μm; the atomic ratio of Ti, Nb and V in the TiNbV high-entropy alloy powder is 1:0.5-2:0.5-2, and the powder particle size range is 53-250 μm.

2. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer according to claim 1, characterized in that, The material of the aluminum alloy component comprises ZL105A, AlSi10Mg, 5A06, 2024, 6061, 5083, 6061 or 7075 aluminum alloy.

3. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an intermediate layer according to claim 1, characterized in that, The material of the titanium alloy component comprises TA2, TA15, TC4, TC11, TC21 or TC18 titanium alloy.

4. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an interlayer according to claim 1, characterized in that, The grooves of the aluminum alloy component and the titanium alloy component are pretreated before laser additive manufacturing.

5. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an interlayer according to claim 1, characterized in that, The groove slope of the groove of the aluminum alloy component forms an angle of 30-60° with the horizontal direction; the groove slope of the groove of the titanium alloy component forms an angle of 30-60° with the horizontal direction.

6. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an interlayer according to claim 1, characterized in that, The TiNbVZr high-entropy alloy powder and the TiNbV high-entropy alloy powder are subjected to drying treatment at 120℃ for 2h before use.

7. The method for laser additive joining of aluminum alloy-titanium alloy components using high-entropy alloy as an interlayer according to claim 1, characterized in that, The process parameters of the laser additive manufacturing process are as follows: laser beam diameter 3-6mm, laser power 2-6KW, scanning speed 500-1500mm / min, single layer height 0.3-0.6mm, overlap rate 30-50%, powder feeding rate 800-2000g / h, and oxygen content less than 80ppm.

8. The method for laser additive joining of aluminum alloy-titanium alloy components with high-entropy alloy as an intermediate layer according to claim 1, characterized in that, After the high-entropy alloy intermediate layer is prepared, an annealing treatment step is further included.

9. The method for laser additive joining of aluminum alloy-titanium alloy components with high-entropy alloy as an intermediate layer according to claim 8, characterized in that, The annealing treatment temperature is 200-500℃, the holding time is 1-6h, and the cooling method is air cooling or furnace cooling.

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