Lightweight metal composite material of automobile exhaust rotor and preparation method of lightweight metal composite material

Abstract

The invention provides a light-weight metal composite material of an automobile exhaust rotor and a preparation method of the light-weight metal composite material, and relates to the field of automobile exhaust rotors, the light-weight metal composite material comprises a high-temperature-resistant outer layer of 1 mm, middle transition copper foil and a light-weight inner layer of 2 mm, metallurgical bonding between the high-temperature-resistant outer layer and the light-weight inner layer is achieved through a diffusion welding process, according to the scheme, through compounding of the high-temperature-resistant outer layer and the light-weight inner side and matching of the specific thickness of each layer, it is guaranteed that the exhaust rotor has good strength, toughness, corrosion resistance, plasticity and high-temperature resistance, meanwhile, the whole exhaust rotor has low density, compared with a traditional Inconel 625 material, the density is smaller, and the service life of the exhaust rotor is prolonged. And the power loss of the engine caused by mass is reduced.

Description

Technical Field

[0001] The present invention relates to the field of automobile exhaust rotors, and in particular to a lightweight metal composite material for automobile exhaust rotors and a preparation method thereof. Background Art

[0002] The exhaust rotor is the rotor inside the air wave supercharger. The air wave supercharger is a pressure converter that allows two gas working fluids to directly contact each other and transfer energy through pressure waves. It is used to boost the gas entering the cylinder by utilizing the energy of the internal combustion engine's exhaust gas when supercharging the internal combustion engine.

[0003] It mainly consists of an air stator, a gas stator, and a rotor. The rotor is driven by the internal combustion engine crankshaft via a belt. When the rotor rotates, the axial air passage formed by the blades on the rotor connects with the high-pressure gas inlet, generating a compression wave. The compression wave propagates along the air passage at the speed of sound, transferring the gas energy to the air in the air passage, increasing the air pressure and density and causing it to flow forward.

[0004] The high-pressure air outlet is located diagonally opposite the high-pressure gas inlet. When the air duct is connected to the high-pressure air outlet, high-pressure air is supplied to the intake pipe of the internal combustion engine. After that, the air duct is connected to the low-pressure gas outlet and the low-pressure air inlet in sequence, completing the gas discharge and fresh air intake, and the rotor continues to rotate to start the next cycle. Currently, the rotor inside the mainstream air wave supercharger is generally made of high-temperature nickel-based alloys such as Inconel 718, which can be used in extremely high temperature and high pressure environments. However, the driving force for the rotation of the rotor is synchronously driven by the crankshaft inside the engine. Due to the high density of high-temperature nickel-based alloys, it will cause a large loss of engine power.

[0005] Therefore, it is necessary to provide a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof to solve the above technical problems. Summary of the Invention

[0006] The present invention provides a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof, which solves the problem that some existing automobile exhaust rotors in the relevant technology cannot provide the characteristics of corrosion resistance, high temperature resistance, fatigue resistance and oxidation resistance during use while being lightweight, resulting in a large loss of engine power.

[0007] In order to solve the above technical problems, the present invention provides a lightweight metal composite material for an automobile exhaust rotor, comprising: a 1mm high-temperature resistant outer layer, an intermediate transition copper foil and a 2mm lightweight inner layer. The metallurgical bonding between the high-temperature resistant outer layer and the lightweight inner layer is achieved through a diffusion welding process.

[0008] Preferably, the high temperature resistant outer layer is one of lnconel 625, lnconel 718, Stellite 6 and Haynes25.

[0009] Preferably, the chemical composition of the lightweight inner layer is Ti-15V-3Cr-3Sn-3Al, including the following components in weight percentage: V 14.2% to 15.5%, Cr 2.2% to 3.2%, Sn 2.6% to 3.2%, Al 2.5 to 3%, Fe≤0.2%, O≤0.15%, H≤0.015%, Si≤0.1%, and the balance is Ti and impurities.

[0010] Preferably, the intermediate transition copper foil is high-purity oxygen-free copper foil.

[0011] A method for preparing a lightweight metal composite material for an automobile exhaust rotor comprises the following steps:

[0012] S1. Raw material preparation:

[0013] Pre-treat the high-temperature resistant outer layer and lightweight inner layer, and cut the copper foil into a size 1-2mm smaller than the welding surface of the workpiece for later use;

[0014] The high temperature resistant outer layer is sandblasted to remove oxide scale and oil stains, and the roughness is controlled within Ra3.2~6.3μm;

[0015] The lightweight inner layer is subjected to stress relief annealing to eliminate processing stress and its surface is roughened by electrolytic etching;

[0016] S2. Raw material assembly:

[0017] The pretreated high-temperature resistant outer layer, lightweight inner layer and intermediate transition copper foil are stacked in sequence to form an overall laminated structure as a sample;

[0018] S3, Diffusion welding:

[0019] The sample was diffusion welded using a vacuum diffusion welding machine, and after welding, the sample was furnace-cooled and the composite material was taken out after cooling to room temperature.

[0020] Preferably, the diffusion temperature of the vacuum diffusion welding machine is 900-1100° C., the pressure is 10-30 MPa, and the diffusion atmosphere is vacuum.

[0021] Preferably, when cutting the copper foil in step S1, a base, a cutting structure and a contrast structure are required;

[0022] The cutting structure includes a placement rack arranged on the top of the base, a sliding rack is arranged on the inner side of the placement rack and can slide up and down, a bidirectional screw rod is arranged laterally on the inner side of the sliding rack, and a connecting sleeve is arranged on the circumferential side of the bidirectional screw rod and can move left and right along its length direction, and a cutting knife is arranged at the bottom of each of the two connecting sleeves.

[0023] Preferably, the comparison structure includes a placement table arranged on the rear side of the top of the base, a positioning frame is provided on the top of the placement table and can slide back and forth, a positioning pressure plate is provided on the inner side of the positioning frame and can slide up and down, a downward pressure spring is provided on the top of the positioning pressure plate and on the inner side of the positioning frame, and a ranging plate is provided on the back of the two connecting sleeves.

[0024] Preferably, a rotating screw is rotatably provided on the inner side of the placement rack, a threaded sleeve is provided on the circumferential side of the rotating screw which can move left and right along its length direction, a connecting plate is rotatably provided on the bottom of the threaded sleeve, and the bottom of the connecting plate is rotatably connected to the top of the sliding rack, a first motor for driving the rotating screw to rotate is provided on the right side of the placement rack, and a second motor for driving the bidirectional screw to rotate is provided on the inner side of the sliding rack.

[0025] Compared with related technologies, the lightweight metal composite material for an automobile exhaust rotor and its preparation method provided by the present invention have the following beneficial effects:

[0026] The present invention provides a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof. By using a composite of a high-temperature-resistant outer layer and a lightweight inner layer, and matching the specific thickness of each layer, the exhaust rotor is ensured to have good strength, toughness, corrosion resistance, plasticity and high-temperature resistance, while having a lower density as a whole. Compared with the traditional Inconel625 material, the density is lower, reducing the loss of mass to engine power. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a preferred embodiment of a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof provided by the present invention;

[0028] Figure 2 for Figure 1 A schematic structural diagram of a front view of the base portion shown;

[0029] Figure 3 for Figure 1 The schematic diagram of the structure of the placement table shown;

[0030] Figure 4 for Figure 1 Schematic diagram of the structure of the rear view of the base part shown.

[0031] Numbers in the figure: 1. Base; 11. Placement rack; 12. Sliding rack; 13. Bidirectional screw; 14. Connecting sleeve; 15. Cutting shear; 16. Rotating screw; 17. Threaded sleeve; 18. Connecting plate; 19. First motor; 20. Second motor; 21. Placement table; 22. Positioning rack; 23. Positioning pressure plate; 24. Downward pressure spring; 25. Distance measuring plate. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 ,in Figure 1 A schematic structural diagram of a preferred embodiment of a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof provided by the present invention; Figure 2 for Figure 1 A schematic structural diagram of a front view of the base portion shown; Figure 3 for Figure 1 The schematic diagram of the structure of the placement table shown; Figure 4 for Figure 1 The structural schematic diagram of the rear view of the base part shown is a lightweight metal composite material for an automobile exhaust rotor and a preparation method thereof.

[0034] First embodiment:

[0035] A lightweight metal composite material for an automobile exhaust rotor comprises a 1 mm high-temperature resistant outer layer, an intermediate transition copper foil, and a 2 mm lightweight inner layer. The metallurgical bonding between the high-temperature resistant outer layer and the lightweight inner layer is achieved through a diffusion welding process.

[0036] The high temperature resistant outer layer is one of lnconel 625, lnconel 718, Stel lite 6 and Haynes 25.

[0037] When the high-temperature exhaust gas from the engine enters the automobile exhaust rotor, it needs to withstand a relatively high temperature, and the rotor blades are arranged in an array, so the high-temperature resistant outer layer needs to be high-temperature resistant, wear-resistant, and have good formability and weldability.

[0038] The chemical composition of the lightweight inner layer is Ti-15V-3Cr-3Sn-3Al, including the following components in weight percentage: V 14.2% to 15.5%, Cr 2.2% to 3.2%, Sn 2.6% to 3.2%, Al 2.5 to 3%, Fe≤0.2%, O≤0.15%, H≤0.015%, Si≤0.1%, and the balance is Ti and impurities.

[0039] Ti-15V-3Cr-3Sn-3Al, referred to as Ti-15-3, is a β-type titanium alloy with a density of ~4.76g / cm 3 It is only about 60% of steel, slightly lower than traditional titanium alloys such as Ti-6Al-4V, but its strength is better than most aluminum alloys and steel, close to or even exceeding Ti-6Al-4V, making it suitable for lightweight design.

[0040] The intermediate transition copper foil is a high-purity oxygen-free copper foil.

[0041] When high-melting-point materials are directly welded to the high-temperature resistant outer layer and the lightweight inner side, the atomic diffusion rate is low, making it difficult to form a uniform metallurgical bond. The melting point of copper foil is as low as 1083°C, and plastic deformation can occur at welding temperatures of usually 700-900°C. The filling interface is microscopically uneven, and the copper atoms have strong diffusion ability, which can act as a "medium" to accelerate the mutual diffusion of the base material atoms on both sides, forming a transition diffusion layer. At the same time, high-purity oxygen-free copper foil can reduce the obstruction of diffusion caused by oxide impurities.

[0042] Second embodiment:

[0043] A method for preparing a lightweight metal composite material for an automobile exhaust rotor comprises the following steps:

[0044] S1. Raw material preparation:

[0045] Pre-treat the high-temperature resistant outer layer and lightweight inner layer, and cut the copper foil into a size 1-2mm smaller than the welding surface of the workpiece for later use;

[0046] Copper foil that is smaller than the welding surface size can prevent edge overflow from affecting the fit. It also needs to be wiped with ethanol to remove the surface rolling oil before use.

[0047] The high temperature resistant outer layer is sandblasted to remove oxide scale and oil stains, and the roughness is controlled within Ra3.2~6.3μm;

[0048] Pretreatment also includes chemical cleaning, oxide removal, water washing and drying.

[0049] The lightweight inner layer is subjected to stress relief annealing to eliminate processing stress and its surface is roughened by electrolytic etching;

[0050] It can be annealed at 500-600℃ for 0.5-1 hour to eliminate processing stress.

[0051] S2. Raw material assembly:

[0052] The pretreated high-temperature resistant outer layer, lightweight inner layer and intermediate transition copper foil are stacked in sequence to form an overall laminated structure as a sample;

[0053] A high-temperature resistant outer layer, a copper foil layer, and a lightweight inner layer form a group of three layers.

[0054] S3, Diffusion welding:

[0055] The sample was diffusion welded using a vacuum diffusion welding machine, and after welding, the sample was furnace-cooled and the composite material was taken out after cooling to room temperature.

[0056] The diffusion temperature of the vacuum diffusion welding machine is 900-1100℃, the pressure is 10-30MPa, and the diffusion atmosphere is vacuum.

[0057] Third embodiment:

[0058] When cutting the copper foil in step S1, a base, a cutting structure and a contrast structure are required;

[0059] The cutting structure includes a placement rack arranged on the top of the base, a sliding rack is arranged on the inner side of the placement rack and can slide up and down, a bidirectional screw rod is arranged laterally on the inner side of the sliding rack, and a connecting sleeve is arranged on the circumferential side of the bidirectional screw rod and can move left and right along its length direction, and a cutting knife is arranged at the bottom of each of the two connecting sleeves.

[0060] The distance between the two connecting sleeves can be adjusted by rotating the bidirectional screw rod, thereby adjusting the distance between the two cutting knives.

[0061] The comparison structure includes a placement table arranged on the rear side of the top of the base, a positioning frame is provided on the top of the placement table and can slide back and forth, a positioning pressure plate is provided on the inner side of the positioning frame and can slide up and down, a downward pressure spring is provided on the top of the positioning pressure plate and on the inner side of the positioning frame, and a ranging plate is provided on the back of the two connecting sleeves.

[0062] The distance measuring plate is located on the back of the connecting sleeve, and the horizontal distance to the cutting knife is 1.5mm. That is, when the rear distance measuring plate is attached to both sides of the high-temperature resistant outer layer or the lightweight inner layer, the distance between the two cutting knives on the front side is just smaller than the width of the rear high-temperature resistant outer layer or the lightweight inner side, so that the copper foil can be cut to a length of less than 1-2mm.

[0063] A rotating screw is rotatably provided on the inner side of the placement rack, and a threaded sleeve is provided on the circumferential side of the rotating screw which can move left and right along its length direction. A connecting plate is rotatably provided on the bottom of the threaded sleeve, and the bottom of the connecting plate is rotatably connected to the top of the sliding rack. A first motor for driving the rotating screw to rotate is provided on the right side of the placement rack, and a second motor for driving the bidirectional screw to rotate is provided on the inner side of the sliding rack.

[0064] The rotation of the second motor drives the rotation of the bidirectional lead screw, which in turn drives the movement of the two connecting sleeves, so that the rear ranging plate is attached to both sides of the high-temperature resistant outer layer or the lightweight inner layer. At this time, the first motor drives the rotating lead screw to rotate, which in turn drives the two threaded sleeves to move, causing the sliding frame to descend, and then the cutting shear is pressed down to cut the copper foil. After a single cutting is completed, the copper foil and the high-temperature resistant outer layer or the lightweight inner layer are rotated 90 degrees and cut again to obtain the copper foil of the required size.

[0065] The working principle of the lightweight metal composite material for automobile exhaust rotor and its preparation method provided by the present invention is as follows:

[0066] Step S1: Raw material preparation:

[0067] Pre-treat the high-temperature resistant outer layer and lightweight inner layer, and cut the copper foil into a size 1-2mm smaller than the welding surface of the workpiece for later use;

[0068] The high temperature resistant outer layer is sandblasted to remove oxide scale and oil stains, and the roughness is controlled within Ra3.2~6.3μm;

[0069] Pretreatment also includes chemical cleaning, oxide removal, water washing and drying.

[0070] The lightweight inner layer is subjected to stress relief annealing to eliminate processing stress and its surface is roughened by electrolytic etching;

[0071] It can be annealed at 500-600℃ for 0.5-1 hour to eliminate processing stress.

[0072] Step S2: Cutting of copper foil:

[0073] When cutting, the copper foil is placed in the positive direction on the top of the base, and the second motor is controlled to drive the bidirectional screw to rotate, thereby driving the connecting sleeve to move relatively, so that the ranging plate on the rear side of the connecting sleeve is attached to both sides of the high-temperature resistant outer layer or the lightweight inner layer. At this time, the distance between the two cutting shears on the front side is just smaller than the width of the high-temperature resistant outer layer or the lightweight inner layer on the rear side, so that the copper foil can be cut to a length of less than 1-2mm. After the initial cutting is completed, the copper foil and the high-temperature resistant outer layer or the lightweight inner layer are rotated 90 degrees again and cut again to obtain the copper foil of the required size.

[0074] Step S3: Raw material assembly:

[0075] The pretreated high-temperature resistant outer layer, lightweight inner layer and intermediate transition copper foil are stacked in sequence to form an overall laminated structure as a sample; the specific stacking order is: one layer of high-temperature resistant outer layer, one layer of copper foil, one layer of lightweight inner layer, and three layers as a group.

[0076] Step S4, diffusion welding:

[0077] The sample was diffusion welded using a vacuum diffusion welding machine. After welding, the sample was furnace-cooled and the composite material was taken out after cooling to room temperature. The diffusion temperature of the vacuum diffusion welding machine was 900-1100° C., the pressure was 10-30 MPa, and the diffusion atmosphere was vacuum.

[0078] Compared with related technologies, the lightweight metal composite material for an automobile exhaust rotor and its preparation method provided by the present invention have the following beneficial effects:

[0079] By using a composite of a high-temperature resistant outer layer and a lightweight inner layer, and matching the specific thickness of each layer, the exhaust rotor is ensured to have good strength, toughness, corrosion resistance, plasticity and high temperature resistance, while having a lower density as a whole. Compared with traditional Inconel 625 material, the density is lower, reducing the loss of mass to engine power.

[0080] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A lightweight metal composite material for an automobile exhaust rotor, characterized in that: include: The 1mm high-temperature resistant outer layer, the intermediate transition copper foil and the 2mm lightweight inner layer are metallurgically bonded through the diffusion welding process.

2. The lightweight metal composite material for automobile exhaust rotor according to claim 1, characterized in that: The high temperature resistant outer layer is one of lnconel 625, lnconel 718, Stellite 6 and Haynes 25.

3. The lightweight metal composite material for automobile exhaust rotor according to claim 1, characterized in that: The chemical composition of the lightweight inner layer is Ti-15V-3Cr-3Sn-3Al, including the following components in weight percentage: V 14.2% to 15.5%, Cr 2.2% to 3.2%, Sn 2.6% to 3.2%, Al 2.5 to 3%, Fe≤0.2%, O≤0.15%, H≤0.015%, Si≤0.1%, and the balance is Ti and impurities.

4. The lightweight metal composite material for an automobile exhaust rotor according to claim 1, characterized in that: The intermediate transition copper foil is a high-purity oxygen-free copper foil.

5. A method for preparing a lightweight metal composite material for an automobile exhaust rotor, characterized in that: The preparation method is used for preparing the lightweight metal composite material according to any one of claims 1 to 4, comprising the following steps: S1. Raw material preparation: Pre-treat the high-temperature resistant outer layer and lightweight inner layer, and cut the copper foil into a size 1-2mm smaller than the welding surface of the workpiece for later use; The high-temperature resistant outer layer is sandblasted to remove oxide scale and oil stains, and the roughness is controlled at Ra3.2~6.3μm; the lightweight inner layer is stress-relief annealed to eliminate processing stress, and the surface is roughened by electrolytic etching; S2. Raw material assembly: The pretreated high-temperature resistant outer layer, lightweight inner layer and intermediate transition copper foil are stacked in sequence to form an overall laminated structure as a sample; S3, Diffusion welding: The sample was diffusion welded using a vacuum diffusion welding machine, and after welding, the sample was furnace-cooled and the composite material was taken out after cooling to room temperature.

6. The method for preparing a lightweight metal composite material for an automobile exhaust rotor according to claim 5, characterized in that: The diffusion temperature of the vacuum diffusion welding machine is 900-1100℃, the pressure is 10-30MPa, and the diffusion atmosphere is vacuum.

7. The method for preparing a lightweight metal composite material for an automobile exhaust rotor according to claim 5, characterized in that: When cutting the copper foil in step S1, a base, a cutting structure and a contrast structure are required; The cutting structure includes a placement rack arranged on the top of the base, a sliding rack is arranged on the inner side of the placement rack and can slide up and down, a bidirectional screw rod is arranged laterally on the inner side of the sliding rack, and a connecting sleeve is arranged on the circumferential side of the bidirectional screw rod and can move left and right along its length direction, and a cutting knife is arranged at the bottom of each of the two connecting sleeves.

8. The method for preparing a lightweight metal composite material for an automobile exhaust rotor according to claim 7, characterized in that: The comparison structure includes a placement table arranged on the rear side of the top of the base, a positioning frame is provided on the top of the placement table and can slide back and forth, a positioning pressure plate is provided on the inner side of the positioning frame and can slide up and down, a downward pressure spring is provided on the top of the positioning pressure plate and on the inner side of the positioning frame, and a ranging plate is provided on the back of the two connecting sleeves.

9. The method for preparing a lightweight metal composite material for an automobile exhaust rotor according to claim 8, characterized in that: A rotating screw is rotatably provided on the inner side of the placement rack, and a threaded sleeve is provided on the circumferential side of the rotating screw which can move left and right along its length direction. A connecting plate is rotatably provided on the bottom of the threaded sleeve, and the bottom of the connecting plate is rotatably connected to the top of the sliding rack. A first motor for driving the rotating screw to rotate is provided on the right side of the placement rack, and a second motor for driving the bidirectional screw to rotate is provided on the inner side of the sliding rack.

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