Tennis racket and preparation method thereof

Abstract

The invention discloses a tennis racket and a preparation method thereof in the technical field of sporting goods manufacturing, and the tennis racket comprises a racket head which is composed of an aluminum alloy outer frame and a foamed aluminum core filled in the aluminum alloy outer frame; the racket rod is made of a composite board formed by alternately laminating a corrosion-resistant high-strength and high-toughness aluminum alloy and a low-density light magnesium alloy; hollow cavities are formed in the racket head in a bilateral symmetry mode, springs are fixedly connected to the sides, close to the top end of the racket head, of the hollow cavities, and a plurality of balance weight bodies capable of freely moving in the length direction of the hollow cavities are placed in the hollow cavities. Static mass is reduced through an aluminum / magnesium alloy composite structure, inertia is enhanced through centrifugal outward movement of the balance weight body during ball hitting, reverse torque is offset through inward movement during braking, and collaborative optimization of swing weight reduction and ball hitting stability is achieved in combination with damping of the foamed aluminum core.

Description

Technical Field

[0001] This invention relates to the field of sports equipment manufacturing technology, specifically to a tennis racket and its manufacturing method. Background Technology

[0002] Tennis relies on power, speed, and precise control, and its equipment has evolved from wood and metal to carbon fiber. Modern competitive tennis places higher demands on racket rigidity, shock absorption, and dynamic center of gravity distribution, and traditional materials still face bottlenecks in balancing lightweight and mechanical performance.

[0003] A search revealed a novel tennis racket and its manufacturing method published in announcement number CN108721849A. The racket includes a frame, a crescent-shaped handle, and a handle. The frame and handle are connected, and a crescent-shaped handle is provided at the connection between the frame and the handle. Several through holes are arranged sequentially along the length of the handle, and weighting material is placed in the through holes. A shell made of foam material is provided on the outside of the handle. The manufacturing method of the novel tennis racket has the following specific steps: (1) preparing yarn, (2) preparing long strips, (3) preparing crescent-shaped handles, (4) pre-shaping, (5) molding, (6) trimming the edges, drilling crescent-shaped holes, sawing the handle, and drawing the film tube, (7) baking again, and (8) assembling. The handle of the tennis racket has through holes, and weighting material can be placed in the holes as needed to adjust to the required weight and balance. A foam handle with a suitable circumference and suitable hardness can be replaced. However, in actual use, the built-in counterweights adjust the center of gravity, but the position of the counterweights is fixed and cannot dynamically adapt to the swing action. When braking, a large inertial torque is still generated, which increases the muscle load of the athlete.

[0004] Therefore, this invention proposes a tennis racket and its manufacturing method to solve the above problems. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a tennis racket and its manufacturing method. By reducing the static mass through a magnesium / aluminum alloy composite structure, the counterweight is centrifugally shifted outward during impact to enhance inertia, and shifted inward during braking to counteract the reverse torque. Combined with the shock absorption of the foam aluminum core, this achieves synergistic optimization of swing weight reduction and impact stability.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a tennis racket and a method for manufacturing the same, comprising: The racket head consists of an aluminum alloy frame and a foam aluminum core filled inside it; The racket shaft is made of a composite sheet material with alternating layers of aluminum alloy and magnesium alloy; The racket head has symmetrical hollow cavities inside. Each hollow cavity is fixedly connected to a spring on the side near the top of the racket head. Each hollow cavity contains several counterweights that can move freely along the length of the hollow cavity.

[0007] The basic scheme principle is as follows: when hitting a ball, the counterweight (such as a steel ball) is compressed by centrifugal force and moves outward to the outside of the racket head, increasing the inertia of hitting the ball; when braking, the spring rebounds to push the counterweight inward, offsetting the reverse torque. The aluminum / magnesium composite structure provides a lightweight matrix, and the foam aluminum core absorbs vibration, forming a "lightweight-dynamic balance-damping" triple synergistic effect.

[0008] The above scheme has the following beneficial effects: 1. Through the dynamic response of the metal counterweight moving outward during hitting and elastically returning during braking, the racket center of gravity can match the mechanical requirements of the swing action in real time. During the hitting stage, the outward movement of the counterweight increases the inertia of the racket head, significantly improving the efficiency of power transmission; during the braking stage, the inward movement of the counterweight shortens the distance between the center of gravity and the handle, effectively offsetting the reverse torque generated during deceleration and reducing the load on the arm muscles. This mechanism breaks through the limitations of traditional fixed counterweights, enabling the racket to balance and control flexibility and hitting power during high-speed swings, especially adapting to the tactical needs of frequent changes in high-intensity confrontation; 2. The composite design of the aluminum alloy outer frame and the foam aluminum core reduces the static mass of the racket head while using the high rigidity of aluminum alloy to resist deformation during hitting, and the porous structure of the foam aluminum absorbs vibration energy through microscopic plastic deformation, reducing the risk of sports injury. The aluminum / magnesium laminated structure of the racket shaft has high specific strength and fatigue resistance through the mechanical complementarity of corrosion-resistant high-toughness aluminum alloy and lightweight magnesium alloy, avoiding the brittle fracture problem caused by lightweight of a single material. The three form a "rigidity-damping-durability" triple guarantee, maintaining structural reliability under competitive lightweight demands and prolonging the service life of the racket.

[0009] Further, the porosity of the foam aluminum core is 50%-70%, the pore size is 0.3-1.2mm, and the aluminum alloy outer frame is combined with the foam aluminum core through diffusion welding.

[0010] Beneficial effects: The 50%-70% porosity foam aluminum core forms a porous energy dissipation network, achieving high-frequency vibration absorption and lightweight synergy; the 0.3-1.2mm pore size ensures the strength of the microstructure, and the diffusion welding interface eliminates stress concentration between dissimilar materials, avoiding delamination failure under the impact of hitting.

[0011] Further, the inner wall of the hollow cavity is coated with one of polytetrafluoroethylene or diamond-like carbon coating.

[0012] Beneficial effects: The polytetrafluoroethylene or diamond-like carbon coating forms an ultra-low friction interface, enabling the metal counterweight to quickly respond to changes in action within the cavity and reducing hysteresis loss; at the same time, the wear-resistant and corrosion-resistant properties of the coating ensure the long-term stability of the cavity, avoiding peeling failure of the coating caused by frequent impact.

[0013] Further, the aluminum / magnesium laminate of the racket shaft comprises at least 3 layers of aluminum alloy layers and magnesium alloy layers stacked alternately, the aluminum alloy layer has a thickness of 0.6 mm, the magnesium alloy layer has a thickness of 0.6-1.0 mm, and the total thickness is 1.8-2.2 mm.

[0014] Beneficial effects: the bionic composite structure is formed by the aluminum / magnesium alternately stacked by at least 3 layers, the high corrosion resistance, high strength and high ductility of the aluminum layer and the light weight, shock absorption and high specific stiffness of the magnesium layer are complementary to each other, and the bending resistance and impact resistance of the racket shaft are significantly improved.

[0015] Further, a shock-absorbing layer is arranged at the connection between the racket head and the racket shaft, the shock-absorbing layer is made of one of silicone and polyurethane elastomer, and has a thickness of 0.5-1.5 mm.

[0016] Beneficial effects: the shock-absorbing layer made of silicone or polyurethane elastomer absorbs the impact energy by high-elastic deformation, and significantly reduces the vibration transmission amplitude to the handle; the viscoelastic property of the shock-absorbing layer can disperse the stress concentration at the connection, and avoid the fatigue fracture risk of the aluminum / magnesium heterogeneous material interface caused by high-frequency vibration.

[0017] Further, the aluminum alloy outer frame has a thickness of 1.0-1.8 mm, and the surface of the outer frame is subjected to anodic oxidation treatment, so that the good corrosion resistance and wear resistance are obtained, and the outer frame can be dyed into various colors to meet different sensory requirements.

[0018] Beneficial effects: the 1.0-1.8 mm aluminum alloy outer frame balances the light weight and impact resistance, the surface anodic oxidation layer resists the ball impact wear and corrosion through high hardness and chemical inertness, prolongs the service life of the outer frame, and the high corrosion-resistant aluminum alloy can also avoid the oxidation failure risk caused by direct exposure.

[0019] Further, the metal counterweight bodies are all steel balls with a diameter of 1.5-2.5 mm.

[0020] Beneficial effects: the 1.5-2.5 mm steel ball balances the inertia adjustment and the movement resistance, the smaller diameter ensures smooth movement in the cavity, the larger single-bead mass enhances the sensitivity of the gravity center adjustment, and the corrosion resistance of the stainless steel material guarantees the functional stability under long-term high-frequency impact.

[0021] Further, the hollow cavity is provided with a limiting filter screen with a hole diameter smaller than the diameter of the steel ball at both ends.

[0022] Beneficial effects: the limiting filter screen prevents the steel ball from leaving the cavity, allows gas to flow to reduce the movement resistance, ensures that the steel ball quickly responds to the changes in the action along the cavity, and isolates the external dust from entering to maintain the long-term airtightness and stability of the self-balancing system.

[0023] Further, a preparation method of a tennis racket comprises the following steps: Step one, die forging aluminum alloy outer frame, and filling the inside with aluminum powder and foaming agent mixture; Step two, heating to 550-600℃ in inert atmosphere, foaming the mixture to form the aluminum foam core, and keeping at 400℃, 50MPa pressure for 2 hours; Step three, laminating the aluminum / magnesium alloy plate through hot isostatic pressing to form the racket handle, pressure 400-600MPa, temperature 250-350℃; Step four, embedding hollow cavity in the reserved position of the racket head, sealing by laser welding, and bonding spring in the hollow cavity, then injecting stainless steel ball into the cavity in vacuum environment, and sealing the two ends with limiting screen; Step five, pre-coating silicone / polyurethane elastomer damping layer at the connection between the bottom end of the racket handle and the racket head, inserting the racket handle into the reserved interface of the racket head, and realizing metallurgical combination of the aluminum alloy outer frame and the magnesium / aluminum laminated plate by laser welding, and cooling to below 80℃ after welding, completing the overall structure assembly.

[0024] Beneficial effects: the preparation method precisely controls the pore structure of the aluminum foam core through die forging-foaming integrated process, realizes metallurgical combination of the aluminum / magnesium laminated interface through hot isostatic pressing, guarantees lightweight and mechanical properties, ensures the airtightness and action response accuracy of the dynamic counterweight system through laser sealing and vacuum bead injection process, breaks through the technical bottleneck of counterweight body jamming and interface delamination in traditional assembly, and realizes efficient and stable mass production of high-performance rackets.

[0025] Further, during the hot isostatic pressing process, the interface between the aluminum alloy layer and the magnesium alloy layer is formed into a groove structure through laser etching, and the groove depth is 10-30μm.

[0026] Beneficial effects: the laser etching groove forms an interface mechanical interlocking and diffusion channel, greatly improves the bonding strength between the aluminum / magnesium layers, and at the same time, the groove structure relieves the stress concentration caused by the difference in thermal expansion, guarantees the fatigue resistance and long-term use stability of the laminated plate.

[0027] Additional aspects and advantages of the application will be made apparent by the following description. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is the overall orthoview of the tennis racket embodiment of the application; Figure 2 It is the front view of the racket head of the tennis racket embodiment of the application; Figure 3 It is an enlarged view of part A of the tennis racket embodiment of the application.

[0029] The reference signs in the drawings of the specification include: 1, a head; 101, an aluminum alloy outer frame; 102, a foam aluminum core; 103, a hollow cavity; 104, a steel ball; 105, a spring; 106, a limiting filter screen; 2, a damping layer; 3, a racket rod. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0031] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0033] The specific embodiments will be described in further detail below: Embodiment 1

[0034] As shown in Figs. Figure 1 , Figure 2 and Figure 3 A tennis racket, comprising: The head 1 is composed of an aluminum alloy outer frame 101 (the aluminum alloy is preferably 5A06) and a foamed aluminum core 102 filled in the inside of the aluminum alloy outer frame 101, wherein the porosity of the foamed aluminum core 102 is 50%-70%, the pore size is 0.3-1.2mm, a porous energy dissipation network is formed, high-frequency vibration absorption and lightweight are coordinated, and the heterogeneous material stress concentration is eliminated by diffusion welding with the aluminum alloy outer frame 101 to avoid delamination failure under the impact of the ball. In addition, the thickness of the aluminum alloy outer frame 101 is 1.0-1.8mm, and since most of the tennis movements are located outdoors and the tennis racket is easy to contact with the ground during the hitting process, the surface of the aluminum alloy outer frame 101 is covered with an anodized layer to resist ball hitting wear and corrosion through high hardness and chemical inertness, prolong the service life of the outer frame, and avoid the risk of oxidation failure caused by direct exposure of the magnesium alloy.

[0035] The racket handle 3 is made of a composite plate material composed of aluminum alloy and magnesium alloy (the aluminum alloy is preferably 5A06, and the magnesium alloy is preferably AZ31), and in order to further improve the bending and impact resistance of the racket handle 3, at least 3 layers of aluminum / magnesium alternating stacks are stacked to form a bionic composite structure, so that the high strength and high ductility of the aluminum layer and the lightweight, shock absorption and high specific stiffness of the magnesium layer are mutually complementary to improve the bending and impact resistance of the racket handle 3, and the thickness of the single aluminum alloy layer is 0.4-0.6mm, the thickness of the single magnesium alloy layer is 0.6-1.0mm, and the total thickness is 1.8-2.2mm, that is, by constraining the stress diffusion path of the interface, the crack propagation across the layers is effectively inhibited, and the balance between lightweight and rigidity demand is effectively balanced, so that the whole tennis racket adapts to the movement characteristics of the tennis ball. As shown in Figure 2 The top end of the racket handle 3 is welded with the bottom end of the head 1.

[0036] The head 1 is internally provided with a hollow cavity 103 which is symmetrically arranged left and right, the hollow cavity 103 is fixedly connected with springs 105 near the top end of the head 1, a plurality of metal counterweights freely movable along the length direction of the hollow cavity 103 are placed in the hollow cavity 103, the metal counterweights are steel balls 104 with a diameter of 1.5-2.5mm, the steel balls 104 are preferably made of 304 stainless steel, and in order to prevent the steel balls 104 from falling out of the cavity and also allow gas to flow to reduce the moving resistance, the steel balls 104 can quickly respond to the changes of the cavity, and the two ends of the hollow cavity 103 are provided with limiting screens 106 with a hole diameter smaller than the diameter of the steel balls 104.

[0037] Since the steel ball 104 needs to slide naturally in the hollow cavity 103 during the movement of the tennis racket, to reduce the occurrence of jamming and make a corresponding response to the swing and stop actions (moving away from the racket 3 and moving towards the racket 3), the inner wall of the hollow cavity 103 is coated with one of polytetrafluoroethylene or diamond-like carbon coating, which forms an ultra-low friction interface to make the steel ball 104 quickly respond to the action change in the cavity, reduce hysteresis loss; at the same time, the wear-resistant and corrosion-resistant properties of the coating ensure the long-term stability of the cavity, avoiding frequent impact leading to peeling failure of the coating.

[0038] In addition, in order to reduce the impact force of the steel ball 104 on the hollow cavity 103 when it is reset, a buffer layer (preferably rubber or sponge) is provided on the side of the hollow cavity 103 away from the spring 105, which buffers the impact force of the steel ball 104 on the magnesium alloy outer frame 101 when it is reset, thereby reducing the burden on the user's wrist caused by the inertial impact of the steel ball 104 when it is reset.

[0039] The specific operation process is as follows: during the swing, the head 1 generates centrifugal force due to acceleration, driving the steel ball 104 to slide along the hollow cavity 103 to the outside of the head 1 (away from one end of the racket 3). At this time, the steel ball 104 compresses the spring 105 to store elastic potential energy, the center of gravity moves outward to reduce the swing resistance and improve the swing speed. When the racket contacts the tennis ball, the steel ball 104 stays on the outside due to inertia, increasing the moment of inertia of the head 1 and significantly improving the efficiency of power transmission; at the same time, the porous aluminum core 102 deforms by bending the hole wall to absorb impact energy, and the rigid support of the aluminum alloy outer frame 101 suppresses deformation, ensuring the accuracy of the shot.

[0040] After the shot, the racket decelerates, the reverse inertia drives the steel ball 104 to move back to the inside of the head 1, and the spring 105 releases potential energy to assist in resetting. The inward movement of the steel ball 104 makes the center of gravity shift towards the handle, offsetting the braking moment of inertia, reducing the arm load and shortening the braking time, providing fast response for continuous shots. The steel ball 104 quickly resets to the initial position under the action of the low-friction coating, ensuring the continuity of the action cycle.

[0041] Specifically, by centrifugal migration and elastic reset of the steel ball 104, the center of gravity distribution is dynamically adjusted to realize self-optimization of swing reduction and shot power. The aluminum / magnesium composite structure, on the basis of light weight, cooperates with the rigid outer frame, porous energy-absorbing core and anti-cracking laminated rod to ensure structural stability; the surface functional coating resists wear and corrosion to maintain long-term operation of the dynamic system.

[0042] The surface functional coating resists wear and corrosion to maintain long-term operation of the dynamic system.

[0043] Some experimental data are as follows: Table 1 - Test item comparison table Test item The present invention Carbon fiber racket Swing weight index (SW, kg-cm2) 290-310 320-350 Ball speed improvement rate +18%-22% +5%-8% Braking load Reduced by 18-23% No significant change Corrosion resistance (salt spray test) No visible corrosion points Significant oxidation and rust Laminate bending strength (MPa) 820-850 Carbon fiber plate: 700-750 Dynamic response time (ms) 15-20 (outward movement) Not applicable Interfacial bonding strength (MPa) 80-120 Gluing structure: 30-50 Example 2:

[0044] The difference from the above examples is that, as shown in Figure 1 , a damping layer 2 is provided at the connection between the head 1 and the handle 3, and the damping layer 2 is made of silicone or polyurethane elastomer, with a thickness of 0.5-1.5mm. The silicone or polyurethane elastomer damping layer 2 absorbs the impact energy of the ball through high-elastic deformation, significantly reducing the amplitude of the vibration transmitted to the handle; its viscoelastic properties can disperse the stress concentration at the connection, avoiding the risk of fatigue fracture of the aluminum / magnesium heterogeneous material interface caused by high-frequency vibration.

[0045] Example 3:

[0046] The difference from the above examples is that a method for manufacturing a tennis racket comprises the following steps: Step one, die forging an aluminum alloy outer frame 101, and filling the inside with a mixture of aluminum powder and foaming agent (TiH2); Step two, heating to 550-600℃ in an inert atmosphere to make the mixture foam into a foamed aluminum core 102, and heat treating at 400℃ and 50MPa pressure for 2 hours to achieve metallurgical bonding between the aluminum alloy and the magnesium alloy; Step three, hot isostatic pressing the aluminum / magnesium laminated sheet to form the handle 3, with a pressure of 400-600MPa and a temperature of 250-350℃; Step four, embedding a hollow cavity 103 in the reserved position of the head 1, sealing it by laser welding, and bonding a spring 105 inside the hollow cavity 103, and then injecting a steel ball 104 into the cavity in a vacuum environment, and sealing the two ends with a limiting screen 106. During the hot isostatic pressing process, the interface between the aluminum alloy layer and the magnesium alloy layer is laser etched to form a groove structure with a depth of 10-30μm, thereby forming an interface mechanical interlocking and diffusion channel, greatly improving the bonding strength between the aluminum / magnesium layers, and the groove structure relieves the stress concentration caused by the difference in thermal expansion, ensuring the fatigue resistance and long-term stability of the laminated sheet; Step five, pre-coating a silicone / polyurethane elastomer damping layer 2 at the connection between the bottom end of the handle 3 and the head 1; inserting the handle 3 into the reserved interface of the head 1, and using laser welding to achieve metallurgical bonding of the aluminum alloy outer frame 101 and the aluminum / magnesium laminated sheet (power 1.2kW, scanning speed 10mm / s, to avoid the heat affected zone penetrating the damping layer 2, i.e. precise heat input to avoid thermal degradation of the damping layer 2, maintaining its viscoelastic properties), and after welding, cooling to below 80℃, completing the assembly of the overall structure.

[0047] The results of the laser etching in step four are as follows: Table 2 - Experimental data table Experiment number Etching depth (μm) Hot isostatic pressing pressure (MPa) Shear strength (MPa) Fatigue life (times) Interface diffusion layer thickness (μm) S1 0 (control group) 400 35.2±2.1 4.8 x 10 5 ]] 2.1±0.3 S2 15 500 49.6±2.8 7.2 x 10 5 ]]> 5.8±0.5 S3 25 550 58.7±3.5 1.1 x 10 6 ]]> 8.3±0.7 According to Table 2, as the laser etching depth increases from 0 μm (S1 control group) to 25 μm (S3 experimental group), the shear strength increases significantly from 35.2 MPa to 58.7 MPa. The groove structure formed by etching increases the aluminum / magnesium interface contact area through the mechanical interlocking effect, while providing a channel for element diffusion (the interface diffusion layer thickness increases from 2.1 μm to 8.3 μm), thereby strengthening the metallurgical bonding. The failure mode of the experimental group changes from "interface peeling" to "matrix fracture", indicating that the interface bonding strength has exceeded the material body strength.

[0048] Obviously, the above embodiments are only examples for clearly illustrating the present application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A tennis racket, characterized in that, include: The racket head consists of an aluminum alloy frame and a foam aluminum core filled inside it; The racket shaft is made of a composite sheet material with alternating layers of aluminum alloy and magnesium alloy; The racket head has symmetrical hollow cavities on both sides. Each hollow cavity is fixedly connected to a spring on the side near the top of the racket head. Each hollow cavity contains several counterweights that can move freely along the length of the hollow cavity.

2. The tennis racket according to claim 1, characterized in that: The aluminum foam core has a porosity of 50%-70% and a pore size of 0.3-1.2mm, and is bonded to the aluminum alloy outer frame by diffusion welding.

3. The tennis racket according to claim 2, characterized in that: The inner wall of the hollow cavity is coated with either polytetrafluoroethylene or diamond-like carbon coating.

4. The tennis racket according to claim 3, characterized in that: The aluminum / magnesium laminate of the racket shaft contains at least three alternating layers of aluminum alloy and magnesium alloy, with the aluminum alloy layer having a thickness of 0.6 mm, the magnesium alloy layer having a thickness of 0.6-0.8 mm, and the total thickness being 1.8-2.2 mm.

5. The tennis racket according to claim 4, characterized in that: A shock-absorbing layer is provided at the connection between the racket head and the shaft. The shock-absorbing layer is made of either silicone or polyurethane elastomer and has a thickness of 0.5-1.5mm.

6. The tennis racket according to claim 5, characterized in that: The aluminum alloy frame of the racket head is 1.0-1.8mm thick, and the aluminum alloy frames of the racket head and shaft are anodized.

7. The tennis racket according to claim 6, characterized in that: The metal counterweights are all steel balls (104) with a diameter of 1.5-2.5 mm.

8. The tennis racket according to claim 7, characterized in that: Both ends of the hollow cavity are equipped with limiting filters with a pore size smaller than that of the steel ball (104).

9. A method for manufacturing a tennis racket, the tennis racket according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Forge an aluminum alloy outer frame and fill it with a mixture of aluminum powder and foaming agent; Step 2: Heat the mixture to 550-600℃ in an inert atmosphere to foam the mixture and form a foamed aluminum core, and keep it at 400℃ and 50MPa pressure for 2 hours. Step 3: The aluminum / magnesium laminate is hot isostatically pressed to form the racket rod, with a pressure of 400-600MPa and a temperature of 250-350℃. Step 4: Embed a hollow cavity in the reserved position of the racket head, seal it by laser welding, and attach a spring inside the hollow cavity. Then, inject the steel ball (104) into the cavity in a vacuum environment and seal both ends with limiting filters. Step 5: Pre-apply a silicone / polyurethane elastomer damping layer to the connection between the bottom end of the racket shaft and the racket head; insert the racket shaft into the reserved interface of the racket head, and use laser welding to achieve metallurgical bonding between the aluminum alloy frame and the aluminum / magnesium laminate. After welding, cool to below 80°C to complete the overall structural assembly.

10. The method for manufacturing a tennis racket according to claim 9, characterized in that, In step three, during the hot isostatic pressing composite process, the interface between the aluminum alloy layer and the magnesium alloy layer is formed by laser etching to create a trench structure with a trench depth of 10-30 μm.

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