Aluminum alloy-titanium alloy component laser additive connection method adopting high-entropy alloy as middle layer

Abstract

The invention discloses a laser additive connection method for an aluminum alloy-titanium alloy component with a high-entropy alloy as a middle layer, and belongs to the technical field of laser additive manufacturing. The connecting method comprises the steps that a V-shaped groove is formed in an aluminum alloy component to be connected and a titanium alloy component to be connected in a machining mode; and preparing a high-entropy alloy intermediate layer at the V-shaped groove by using TiNbVZr or TiNbV high-entropy alloy powder through a laser additive manufacturing process so as to connect the aluminum alloy component and the titanium alloy component. According to the method, the middle layer of the aluminum alloy-titanium alloy component is prepared from the high-entropy alloy with the two preferable components in a laser additive manufacturing mode, generation and cracking of intermetallic compounds in the aluminum alloy-titanium alloy direct laser connection process are avoided, and then the bonding strength of a connection area of the aluminum alloy-titanium alloy component is remarkably improved.

Description

Technical Field

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

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

[0003] At present, the manufacture of aluminum alloy-titanium alloy component connections mainly relies on traditional welding methods, including diffusion welding, ultrasonic welding, arc brazing, etc., and its typical disadvantage is that the bonding strength of the welding connection area is low, and the tensile strength is generally only 10-30MPa. Due to the significant physical and chemical differences between aluminum alloys and titanium alloys, the welding of aluminum / titanium dissimilar structures is extremely difficult. A large amount of brittle intermetallic compounds will be generated at the interface of the dissimilar alloys, and traditional laser / electron beam melting welding technologies cannot be used, which will greatly limit the application of aluminum alloy-titanium alloy component connections.

[0004] Due to its high mixing entropy, slow diffusion rate of hysteretic diffusion and high stability, high entropy alloys can make Al and Ti elements tend to form solid solutions without precipitating intermetallic compounds, while alleviating the difference in physical properties between aluminum alloys and titanium alloys, thus becoming a candidate material for the intermediate layer of aluminum alloy-titanium alloy connection. The use of laser additive manufacturing technology to prepare high entropy alloy intermediate layers to achieve aluminum alloy-titanium alloy component connection can avoid the formation of TiAl-based brittle intermetallic compounds in the connection area and interface cracking in the connection area, thereby preparing high-performance aluminum alloy-titanium alloy component connectors. At the same time, there are many high entropy alloy component systems, and a high entropy alloy system that can simultaneously dissolve high contents of Al and Ti must be found to achieve a better connection effect. Summary of the invention

[0005] The purpose of the present invention is to provide a laser additive connection method for aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer. Two high entropy alloys of preferred compositions are made into an intermediate layer of an aluminum alloy-titanium alloy component by laser additive manufacturing, thereby avoiding the generation and cracking of intermetallic compounds during the direct laser connection of the aluminum alloy-titanium alloy, thereby significantly improving the bonding strength of the connection area of ​​the aluminum alloy-titanium alloy component.

[0006] To achieve the above object, the present invention provides the following technical solutions:

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

[0008] The aluminum alloy component and the titanium alloy component to be connected are prepared with a V-shaped groove by mechanical processing; a high-entropy alloy intermediate layer is prepared at the V-shaped groove by a laser additive manufacturing process using TiNbVZr or TiNbV high-entropy alloy powder 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 grades of aluminum alloys such as ZL105A, AlSi10Mg, 5A06, 2024, 6061, 5083, 6061, and 7075.

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

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

[0012] Preferably, the bevel surface of the groove of the aluminum alloy component forms an angle of 30-60° with the horizontal direction; the bevel surface 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 53-250 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.

[0014] More preferably, the TiNbVZr high entropy alloy powder and the TiNbV high entropy alloy powder are dried at 120° C. for 2 hours before use.

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

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

[0017] More preferably, the annealing treatment is carried out at a temperature of 200-500° C., with a holding time of 1-6 hours, and air cooling or furnace cooling.

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

[0019] The present invention provides a laser additive connection method for aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer. The provided method uses TiNbVZr or TiNbV high entropy alloy as a filling material for the aluminum alloy-titanium alloy component connection area for the first time. The TiNbVZr or TiNbV high entropy alloy intermediate layer prepared by the laser additive manufacturing process avoids the generation and cracking of TiAl-based brittle intermetallic compounds during the direct additive connection of aluminum alloy and titanium alloy, and can prepare aluminum alloy-titanium alloy components with 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 other dissimilar metals such as titanium / steel, nickel / steel, titanium / nickel, and can be promoted and implemented in its related fields. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0022] Figure 3 This is a schematic diagram of an aluminum alloy component and a titanium alloy component with a V-shaped groove connected through 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] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

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

[0026] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] Schematic diagram of aluminum alloy components and titanium alloy components with V-shaped grooves prepared by mechanical processing in the embodiment of the present invention is shown in Figure 1 ; Schematic diagram of using laser additive manufacturing process to prepare a high entropy alloy intermediate layer connecting an aluminum alloy component with a V-shaped groove and a titanium alloy component. Figure 2 ; A schematic diagram of an aluminum alloy component with a V-shaped groove and a titanium alloy component connected via a high entropy alloy intermediate layer is shown in Figure 3 .

[0029] 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.

[0030] The high entropy alloy intermediate layer in the embodiment of the present invention is manufactured by LMD-V type laser forming manufacturing system. The specific operation of the system is: the aluminum alloy component and the titanium alloy component with processed grooves are fixed on Figure 2 On the workbench 5 of the LMD-V laser additive manufacturing equipment shown, high entropy alloy powder is used as the intermediate layer material of the laser additive connection area. The high entropy alloy powder is a pre-alloyed powder with a powder particle size of 53-250μm. The entire laser additive connection preparation process is carried out in an inert gas protection atmosphere.

[0031] Example 1

[0032] Steps for connecting ZL105A aluminum alloy components and TC11 titanium alloy components with TiNbVZr high entropy alloy intermediate layer:

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

[0034] S2. Pre-treat the TiNbVZr high entropy alloy powder: place it in a vacuum oven for drying at 120°C for 2 hours to remove moisture and increase the fluidity of the powder during the molding process.

[0035] S3. The aluminum alloy component and the titanium alloy component to be connected are machined to prepare a 45° groove, and the component dimensions are 60mm×40mm×20mm. The two groove parts and their surrounding areas are polished with sandpaper until the metallic luster is revealed, and then wiped with alcohol to remove surface oil stains.

[0036] S4. According to the size of the groove of the TC11 titanium alloy and the ZL105A to be connected, set the scanning path of the intermediate high entropy alloy connection area. Import the completed laser additive manufacturing process file into the control system of the equipment. The process parameters for depositing the high entropy alloy intermediate layer are: laser beam diameter of 6mm, laser power of 3.5KW, scanning speed of 1000mm / min, single layer lifting height of 0.5mm, powder feeding rate of 1000g / h, and overlap rate of 40%.

[0037] S4. Fix the TC11 titanium alloy and ZL105A parts to be connected on the machine tool workbench, and introduce inert gas Ar gas to maintain the oxygen content in the entire molding environment below 80ppm.

[0038] After the laser additive joining of S5, TC11 titanium alloy and ZL105A aluminum alloy is completed, the laser additive joining samples are 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] Steps for connecting ZL105A aluminum alloy components and TC11 titanium alloy components with TiNbV high entropy alloy intermediate layer:

[0041] Compared with Example 1, the only difference is that the equiatomic ratio TiNbV high entropy alloy powder is used to replace the equiatomic ratio TiNbVZr high entropy alloy powder.

[0042] The tensile properties of the material obtained by connecting the aluminum alloy component and the titanium alloy component using a high entropy alloy intermediate layer in Test Example 1-2 are shown in Table 1.

[0043] Table 1 Tensile properties of high entropy alloy intermediate layer connecting aluminum alloy components and titanium alloy components

[0044]

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

[0046] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A laser additive joining method for aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer, characterized in that: The following steps are involved: 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.

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

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

4. The laser additive joining method of aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer according to claim 1 is characterized in that: The grooves of the aluminum alloy component and the titanium alloy component are pre-treated before laser additive manufacturing.

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

6. The laser additive joining method of aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer according to claim 1, characterized in that: 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.

7. The laser additive joining method of aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer according to claim 6, characterized in that: The TiNbVZr high entropy alloy powder and the TiNbV high entropy alloy powder are dried at 120° C. for 2 hours before use.

8. The laser additive joining method of aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer according to claim 1, characterized in that: 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, and oxygen content less than 80ppm.

9. The laser additive joining method of aluminum alloy-titanium alloy components using a 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 step is also included.

10. The laser additive joining method of aluminum alloy-titanium alloy components using a high entropy alloy as an intermediate layer according to claim 9, characterized in that: The annealing treatment is carried out at a temperature of 200-500° C., with a holding time of 1-6 hours, and air cooling or furnace cooling.

Images