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CN-122008563-A - Ultrasonic welding method for carbon fiber reinforced thermoplastic resin composite material

CN122008563ACN 122008563 ACN122008563 ACN 122008563ACN-122008563-A

Abstract

The invention relates to the technical field of ultrasonic welding of composite materials, in particular to an ultrasonic welding method of a carbon fiber reinforced thermoplastic resin composite material. The method comprises the steps of 1) applying thermoplastic resin powder with the particle size of 15-25 mu m and meeting D 50 to the surface of an interface to be welded, enabling the thermoplastic resin powder to form an energy guiding layer on the interface, 2) enabling the interface to be welded under the action of ultrasonic vibration, melting the energy guiding layer under the action of the ultrasonic vibration, and enabling the interface to be connected. The method can obviously reduce the unwelded defect, improve the interface integrity and mechanical strength of the welded joint, is suitable for planar connection, is suitable for ultrasonic welding of curved surfaces and complex three-dimensional surface structures, and has the advantages of simple process, strong applicability and stable connection quality.

Inventors

  • LI XIAODONG
  • Lv Yufang
  • DU HUIZHEN
  • XIONG WEI
  • YU JINGUANG

Assignees

  • 南京方硕复合材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260305

Claims (10)

  1. 1. A method of ultrasonic welding of a carbon fiber reinforced thermoplastic resin composite, the method comprising: 1) Applying thermoplastic resin powder with the particle size of 15-25 mu m and meeting D 50 to the surface of an interface to be welded, so that an energy-conducting layer is formed on the interface by the thermoplastic resin powder; 2) And welding the interface under the action of ultrasonic vibration, and melting the energy-conducting layer under the action of ultrasonic vibration and connecting the interface.
  2. 2. The method of claim 1, wherein the thermoplastic resin powder is a polyaryletherketone resin or a polyarylethernitrile resin powder containing a nitrile structure; Preferably, the polyaryletherketone resin is PEEK; Preferably, the poly (arylene ether nitrile ketone) resin is poly (arylene ether nitrile ketone) resin containing a phenolphthalein structure.
  3. 3. The method according to claim 1, wherein the thermoplastic resin powder has an areal density of an energy conductive layer formed at the interface of 5 to 20 g/m 2 .
  4. 4. The method of claim 1, wherein the matrix resin of the composite is selected from the group consisting of Polyaryletherketone (PAEK) resins, polyphenylene sulfide (PPS) resins, polyetherimide (PEI) resins, polyarylsulfone (PSU) resins, polyphenylsulfone (PES) resins, polyphenylsulfone (PPSU) resins, and blends or modified systems thereof.
  5. 5. The method according to claim 1 to 4, wherein the thermoplastic resin powder is applied to the interface to be welded by preheating, and the interface region of the composite material is heated to a temperature within the range of glass transition temperature (Tg) + -10 ℃ of the matrix resin, so that the surface of the thermoplastic resin powder is slightly softened and is primarily adhesively fixed to the interface surface.
  6. 6. The method of any one of claims 1-4, wherein applying the thermoplastic resin powder to the interface surface comprises electrostatically adhering the powder to the interface surface.
  7. 7. The method according to any one of claims 1-4, wherein the surface of the interface to be welded is a non-planar structure, preferably selected from curved, hyperbolic, curvature-changing or complex three-dimensional surfaces with stepped shape.
  8. 8. The method according to any one of claims 1-4, wherein the frequency of the ultrasonic vibration is 15-40 kHz.
  9. 9. The method according to any one of claims 1-4, wherein the welding pressure is 0.5-3 MPa.
  10. 10. The method of any of claims 1-4, wherein the welding time is 1-5 s and the post-welding dwell time is 1-5 s.

Description

Ultrasonic welding method for carbon fiber reinforced thermoplastic resin composite material Technical Field The invention relates to the technical field of ultrasonic welding of composite materials, in particular to an ultrasonic welding method of a carbon fiber reinforced thermoplastic resin composite material. Background Carbon fiber reinforced thermoplastic resin composite materials (CFRT, carbon Fiber Reinforced Thermoplastics) have been widely used in the fields of aerospace, rail transit, automobile weight reduction, unmanned aerial vehicle structural members and the like because of the characteristics of high specific strength, high specific modulus, good impact resistance, hot-melt reprocessability, repairability, good recyclability and the like. With the increasing proportion of composite materials in the load-bearing structure, the connection mode between different components becomes one of the key factors affecting the reliability and service life of the overall structure. The existing connection mode of the carbon fiber reinforced thermoplastic composite material mainly comprises three types of mechanical connection, cementing connection and fusion welding connection. Mechanical connection is convenient to assemble, but stress concentration is introduced and fiber continuity is damaged, so that mechanical properties of materials are reduced, the quality of a cementing connection interface depends on surface treatment, heat resistance and long-term environmental adaptability are insufficient, and the requirements of high-temperature structural members are difficult to meet. In contrast, ultrasonic welding is used as a melting connection mode without an external adhesive layer, can realize rapid melting and solidification of interface resin in a short time, has the characteristics of high connection efficiency, stable interface performance and good repeatability, and therefore becomes an important development direction of thermoplastic composite material connection. However, existing ultrasonic welding of composite materials relies heavily on prefabricated Energy Directors (EDs) to achieve interfacial Energy concentration to promote rapid melting of the interface. Typical energy conductive layer forms include thermoplastic resin films, ribs of wedge structures, three-dimensional fabrics or nonwovens, and the like. The energy guiding layer has a certain effect in plane or regular surface connection, but has the following defects in a curved surface, a hyperboloid or a three-dimensional interface with a complex step structure: 1) The special-shaped surface is difficult to attach, the film or the ribs are difficult to attach completely at the interface, and an unwelded area is easy to generate; 2) The shape of the energy-conducting layer is fixed, and the interface roughness and micro holes cannot be automatically adapted on a microscopic scale; 3) The existing energy guide layer needs prefabrication, cutting and positioning, has complex process and high assembly precision requirement; 4) When the interface structure is complex, the ultrasonic energy is not uniformly transmitted at the interface, and the melting is discontinuous, so that the problems of stress concentration and strength reduction of the welding line are caused. Disclosure of Invention The invention comprises the following technical scheme: The invention relates to an ultrasonic welding method of a carbon fiber reinforced thermoplastic resin composite material, which comprises the following steps: 1) Applying thermoplastic resin powder with the particle size of 15-25 mu m and meeting D 50 to the surface of an interface to be welded, so that an energy-conducting layer is formed on the interface by the thermoplastic resin powder; 2) And welding the interface under the action of ultrasonic vibration, and melting the energy-conducting layer under the action of ultrasonic vibration and connecting the interface. According to the invention, the thermoplastic resin powder with the particle size of 15-25 mu m is applied to the interface to be welded to form the energy guiding layer, so that the powder can conform to the shape of the interface and can be melted and permeated rapidly under the action of ultrasonic vibration, thereby forming a uniform, continuous and compact resin bridging layer at the interface to realize stable energy transfer and effective interface fusion, thereby remarkably reducing the unwelded defects, improving the interface integrity and mechanical strength of the welded joint, being suitable for planar connection and simultaneously being suitable for ultrasonic welding of curved surfaces and complex three-dimensional surface structures, and having the advantages of simple process, strong applicability and stable connection quality. Drawings In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embo