A method for bonding and repairing surfaces with epoxy resin

Abstract

The invention relates to an epoxy-resin surface bonding and repairing method. The method includes the steps that a carbon nanometer tube, epoxy resin and acetone are mixed to be even in the mass ratio of (1-2):(2-5):(90-110), and an epoxy-resin dilute solution is obtained; the epoxy-resin dilute solution is sprayed to a to-be-repaired surface multiple times, and a pretreatment layer is obtained; the epoxy and a curing agent are mixed to be even, the pretreatment layer is coated with the product till the epoxy is completely cured, and the epoxy-resin surface bonding and repairing is completed. According to the epoxy-resin surface bonding and repairing method, the epoxy resin with the added carbon nanometer tube is diluted with acetone, the mobility and the wettability of the epoxy resin are improved, and the carbon nanometer tube is completely coated by the epoxy resin and permeates into minimum gaps of a bonded or repaired surface, and the epoxy resin is cured through the diffusion effect of the curing agent; meanwhile, due to extruding, the small part of carbon nanometer tube in the gaps can enter post-covered epoxy resin, a gap-free and bubble-free bonding layer is formed, and the strength of a bonding interface is improved.

Description

[0001] 【Technical field】 [0002] The invention relates to the field of surface repair, in particular to a method for bonding and repairing surfaces with epoxy resin. [0003] 【Background technique】 [0004] Epoxy resin has strong cohesion, dense molecules, and good mechanical properties. And it contains polar groups such as epoxy group and hydroxyl group with great activity, which makes it have excellent adhesive performance. In addition, epoxy resin also has the advantages of strong chemical corrosion resistance and good electrical insulation, which determines that epoxy resin occupies an important position in national production. Composite materials made of epoxy resin have a series of advantages such as good mechanical properties, light weight, high specific strength and specific stiffness, making them widely used in automobiles, aviation and other fields. Especially in the field of aviation, the weight of the airframe determines the fuel consumption rate and thus determi...

AI Technical Summary

Problems solved by technology

In the current bonding process, due to the lack of fluidity of the epoxy resin, it cannot penetrate into the surface pits or gaps, so that the epoxy resin cannot completely contact the rough bonding or repairing surface. After the epoxy resin is cured, it will be in the Gap at contact interface

like figure 1 As shown, if during the repair process, the gap defect 2 (early crack) will be formed at the bonding interface because the epoxy resin cannot penetrate deep into the gap of the repaired surface, which will have a serious impact on the safety of the aircraft

In addition, due to the poor wettability and fluidity of the epoxy resin, the carbon nanotubes 4 cannot be completely wrapped, so that the carbon nanotubes 4 will generate air bubbles 5 during the mixing process with the epoxy resin, and the presence of air bubbles on the surface of the carbon nanotubes and gaps on the bonding surface will cause serious problems. Cause stress concentration at the bonding interface and reduce the bonding strength

Because the direct mixing of carbon nanotubes and epoxy resin is prone to defects such as bubbles, and the viscous resin is generally difficult to enter the carbon nanotube aggregates, the current method is to mix by mechanical extrusion, or use chemical treatment methods, such as Carbon nanotubes are functionalized to improve the uniform distribution of carbon nanotubes in epoxy resin and reduce aggregates. Therefore, the existing treatment process is relatively complicated and not conducive to on-site operations

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