Welding method of resin-based composite material for realizing reinforced fiber connection

Abstract

The invention discloses a welding method of a resin-based composite material for realizing reinforced fiber connection, and relates to the field of welding methods of resin-based composite materials. The method aims at solving the technical problem that at present, a joint of a resin-based composite material obtained through traditional ultrasonic welding is low in strength. The method comprises the following steps: 1, selecting a joint form and processing a composite material; secondly, the to-be-welded area is heated, the resin matrix of the to-be-welded area is removed, and the reinforced fibers are exposed; thirdly, the reinforced fibers are welded through a horizontal vibration ultrasonic welding method, so that the reinforced fibers are connected; fourthly, after the fibers are connected, resin is poured again in the welding area. According to the invention, the connection of the resin matrix is realized, the connection of the carbon fibers in the resin matrix is also realized, and the obtained joint is high in strength; by means of the method, welding of various composite materials such as carbon fiber / glass fiber and other resin-based composite materials can be achieved. The method is used for welding the reinforced fiber connected resin-based composite material.

Description

Technical Field

[0001] The invention relates to the field of welding methods for resin-based composite materials. Background Art

[0002] Resin-based composite materials are widely used in aerospace, advanced manufacturing and other fields due to their low density and high strength. Similar to other materials, it is also difficult to achieve one-time molding of complex structures in resin-based composite materials during application. Therefore, welding or bonding methods are often required in actual applications to prepare simple resin-based composite parts into complex components for practical application. There are many welding methods for resin-based composite materials, such as induction welding, ultrasonic welding and resistance welding. At present, the most widely used welding method for resin-based composite materials is ultrasonic welding, which has the advantages of high welding efficiency, low welding cost and simple operation.

[0003] However, in the traditional ultrasonic welding process, whether or not energy conductors are used, the welding process only achieves the connection between the resins, but does not achieve the effective connection of the internal fibers, such as carbon fibers or glass fibers. Therefore, the joint strength of the resin-based composite material obtained by traditional ultrasonic welding is generally low. Summary of the invention

[0004] In order to solve the technical problem that the joint strength of the resin-based composite material obtained by conventional ultrasonic welding is relatively low, the present invention provides a welding method for a resin-based composite material for connecting reinforcing fibers.

[0005] A method for welding a resin-based composite material to achieve reinforcing fiber connection is specifically carried out in the following steps:

[0006] 1. Pre-clamp the to-be-welded joint of the resin-based composite material, heat the to-be-welded area, remove the resin matrix in the to-be-welded area, and expose part of the reinforcing fibers;

[0007] 2. Welding the exposed reinforcing fibers of the joint to be welded processed in step 1 by horizontal vibration ultrasonic welding to connect the reinforcing fibers of the joint to be welded together;

[0008] 3. Re-pour resin into the reinforcing fibers connected in step 2, vibrate to assist filling during pouring, and apply pressure to form after pouring to complete.

[0009] Furthermore, the resin-based composite material in step 1 is carbon fiber / glass fiber reinforced polyphenylene sulfide or carbon fiber / glass fiber reinforced polyetheretherketone.

[0010] Furthermore, the heating temperature in step 1 is 20 to 50° C. higher than the melting point of the resin matrix in the resin-based composite material.

[0011] Furthermore, the welding process parameters of step 2 are: ultrasonic power of 100-3000W, pre-ultrasonic pressure holding time of 0.1s-100s; ultrasonic time of 0.01s-100s; ultrasonic head pressure of 0.01MPa-2MPa; ultrasonic frequency of 15kHz-60kHz, ultrasonic amplitude of 1μm-100μm.

[0012] Furthermore, in step three, the parameters for controlling vibration are: power of 10 to 3000 W, vibration time of 10 s to 100 s; vibration frequency of 15 Hz to 60 kHz, and amplitude of 1 μm to 1 mm.

[0013] Furthermore, the pressure applied in step three is 0.01 MPa to 5 MPa.

[0014] The present invention realizes high-strength welding of fiber-reinforced resin-based composite materials by removing resin, ultrasonic welding of reinforcing fibers, and pouring resin. The present invention is divided into the following steps: first, selecting the joint form and the processing of the composite material; second, heating the area to be welded, removing the resin matrix in the area to be welded, and exposing the reinforcing fibers; third, welding the reinforcing fibers using a horizontal vibration ultrasonic welding method to connect the reinforcing fibers; fourth, after the fibers are connected, re-pouring resin in the welding area, using vibration and pressurization to achieve good filling of the resin between the fibers, and finally completing the welding.

[0015] Beneficial effects of the present invention:

[0016] In order to obtain high-strength resin-based composite material joints and promote their wide application in the current manufacturing industry, the present invention proposes a new multi-step welding method for resin-based composite materials. The method can achieve the connection of reinforcing fibers inside the resin-based composite material and effectively improve the joint strength of the resin-based composite material.

[0017] In the welding process of the present invention, the resin at the position to be welded is first removed to expose the reinforcing fibers, and then the reinforcing microstructures are directly welded using a horizontal ultrasonic vibration welding method. Ultrasonic welding can achieve the welding of many new materials and difficult-to-weld materials such as metals and ceramics, so it can achieve direct bonding of carbon fibers or glass fibers. After the internal microstructures are connected using ultrasonic vibration, resin is poured thereon, and a method of combining pressurization and vibration is used to achieve a tight assembly of the resin and the fibers. Finally, a high-strength joint of a resin-based composite material is obtained.

[0018] 1. The present invention does not require special resin molding technology or equipment and has low cost;

[0019] 2. The present invention not only realizes the connection of the resin matrix, but also realizes the connection of the carbon fibers inside it, and the obtained joint has high strength;

[0020] 3. This method can realize the welding of various composite materials, such as carbon fiber / glass fiber and other resin-based composite materials.

[0021] The invention is used for welding of resin-based composite materials with reinforced fiber connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A joint form for pre-clamping a pair of resin-based composite materials to be welded

[0023] Figure 2 A schematic diagram of a specific embodiment 1 in which the resin matrix of the area to be welded is removed to expose part of the reinforcing fibers;

[0024] Figure 3 It is a schematic diagram of horizontal vibration welding of reinforcing fibers in a specific embodiment 1;

[0025] Figure 4 It is a schematic diagram of pouring and applying pressure to form a specific embodiment of the present invention;

[0026] Figure 5 Characteristic images of weld joint cross sections were obtained for the examples. DETAILED DESCRIPTION

[0027] Specific implementation method 1: This implementation method is a method for welding a resin-based composite material to achieve reinforcing fiber connection, which is specifically carried out in the following steps:

[0028] 1. Pre-clamp the to-be-welded joint of the resin-based composite material, heat the to-be-welded area, remove the resin matrix in the to-be-welded area, and expose part of the reinforcing fibers;

[0029] 2. Welding the exposed reinforcing fibers of the joint to be welded processed in step 1 by horizontal vibration ultrasonic welding to connect the reinforcing fibers of the joint to be welded together;

[0030] 3. Re-pour resin into the reinforcing fibers connected in step 2, vibrate to assist filling during pouring, and apply pressure to form after pouring to complete.

[0031] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the resin-based composite material in step 1 is carbon fiber / glass fiber reinforced polyphenylene sulfide or carbon fiber / glass fiber reinforced polyetheretherketone. The rest is the same as specific embodiment 1.

[0032] Specific implementation method three: This implementation method is different from specific implementation method one or two in that: in step one, the pre-clamping overlaps the resin-based composite material, and the overlap width is 10 mm. Other aspects are the same as specific implementation method one or two.

[0033] Specific embodiment 4: This embodiment is different from specific embodiments 1 to 3 in that the heating temperature in step 1 is 20 to 50° C. higher than the melting temperature of the resin matrix in the resin-based composite material. The rest is the same as specific embodiments 1 to 3.

[0034] Specific implementation mode 5: This implementation mode is different from the specific implementation modes 1 to 4 in that: in step 1, tweezers or a cutter are used to remove the heated and melted resin matrix. The rest is the same as the specific implementation modes 1 to 4.

[0035] Specific implementation method 6: This implementation method is different from specific implementation methods 1 to 5 in that: in step 2, the exposed reinforcing fibers of the joint to be welded are staggered and overlapped. The rest is the same as specific implementation methods 1 to 5.

[0036] Specific embodiment 7: This embodiment is different from specific embodiments 1 to 6 in that: the process parameters of the welding described in step 2 are: the power of the ultrasonic wave is 100 to 3000 W, the holding time before ultrasonic wave is 0.1s to 100s; the ultrasonic time is 0.01s to 100s; the pressure of the ultrasonic head is 0.01MPa to 2MPa; the frequency of the ultrasonic wave is 15kHz to 60kHz, and the amplitude of the ultrasonic wave is 1μm to 100μm. The rest is the same as specific embodiments 1 to 6.

[0037] Specific implementation eight: This implementation differs from specific implementations one to seven in that in step three, the ultrasonic head is first removed, and then the resin is re-poured into the welding area. The rest is the same as specific implementations one to seven.

[0038] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that: the parameters for controlling vibration in step 3 are: power of 10 to 3000 W, vibration time of 10 s to 100 s, vibration frequency of 15 Hz to 60 kHz, and amplitude of 1 μm to 1 mm. Others are the same as specific embodiments 1 to 8.

[0039] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the pressure applied in step 3 is 0.01 MPa to 5 MPa. The rest is the same as specific embodiments 1 to 9.

[0040] The content of the present invention is not limited to the content of the above-mentioned embodiments. The combination of one or several specific embodiments can also achieve the purpose of the invention.

[0041] Example:

[0042] A method for welding a resin-based composite material to achieve reinforcing fiber connection is specifically carried out in the following steps:

[0043] 1. The welded parts are two pieces of resin-based composite materials (carbon fiber reinforced PPS) with a size of 80mm×30mm×4mm. The two pieces of the parent materials are overlapped and placed, and the overlap width is set to 10mm. The welding area is heated at 320℃ until the PPS matrix is ​​melted. The melted resin is removed with tweezers, knives, etc. to expose the carbon fibers in the matrix.

[0044] 2. The exposed carbon fiber of the welded joint processed in step 1 is welded by horizontal vibration ultrasonic welding. The welding parameters are as follows: the ultrasonic power is 300W, the pressure holding time before ultrasonic is 1s; the ultrasonic time is 0.05s; the pressure of the ultrasonic head is 0.2MPa; the ultrasonic frequency is 25kHz, and the ultrasonic amplitude is 20μm. The carbon fiber of the welded joint is connected together;

[0045] 3. Step 2 After welding, remove the ultrasonic head and pour PPS resin into the welding area. Vibration is used to assist filling during pouring. The vibration frequency is 100 Hz. After pouring, 0.1 MPa pressure is applied to form the welded joint.

[0046] Figure 5 The figure shows the characteristic diagram of the cross section of the welded joint. It can be seen from the figure that the carbon fibers are bonded together and there is obvious welding between different carbon fibers. This is due to the effect of ultrasound in step two.

[0047] The mechanical property of the joint obtained in the embodiment is 75.3 MPa, which is more than double the joint strength obtained by the ultrasonic welding method (maximum about 35 MPa) in the current lap joint form.

Claims

1. A method for welding a resin-based composite material for achieving reinforcing fiber connection, characterized in that The method is specifically carried out in the following steps:

1. Pre-clamp the to-be-welded joint of the resin-based composite material, heat the to-be-welded area, remove the resin matrix in the to-be-welded area, and expose part of the reinforcing fibers; 2. Welding the exposed reinforcing fibers of the joint to be welded processed in step 1 by horizontal vibration ultrasonic welding to connect the reinforcing fibers of the joint to be welded together; 3. Re-pour resin into the reinforcing fibers connected in step 2, vibrate to assist filling during pouring, and apply pressure to form after pouring to complete.

2. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that The resin-based composite material in step 1 is carbon fiber / glass fiber reinforced polyphenylene sulfide or carbon fiber / glass fiber reinforced polyetheretherketone.

3. A welding method for resin-based composite materials for achieving reinforcing fiber connection according to claim 1, characterized in that The pre-clamping in step 1 overlaps the resin-based composite material, and the overlap width is 10 mm.

4. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that The heating temperature in step 1 is 20 to 50° C. higher than the melting point of the resin matrix in the resin-based composite material.

5. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that Step 1: Use tweezers or a knife to remove the heated and molten resin matrix.

6. A welding method for resin-based composite materials for achieving reinforcing fiber connection according to claim 1, characterized in that Step 2: Stagger and overlap the exposed reinforcing fibers of the joint to be welded.

7. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that The welding process parameters in step 2 are: ultrasonic power of 100-3000W, pre-ultrasonic pressure holding time of 0.1s-100s; ultrasonic time of 0.01s-100s; ultrasonic head pressure of 0.01MPa-2MPa; ultrasonic frequency of 15kHz-60kHz, and ultrasonic amplitude of 1μm-100μm.

8. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that Step 3: Remove the ultrasonic head first and then re-pour the resin into the welding area.

9. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that Step 3: The parameters for controlling vibration are: power of 10 to 3000 W, vibration time of 10 to 100 s, vibration frequency of 15 Hz to 60 kHz, and amplitude of 1 μm to 1 mm.

10. A method for welding a resin-based composite material for achieving reinforcing fiber connection according to claim 1, characterized in that The pressure applied in step 3 is 0.01MPa~5MPa.

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