碳纤维表面处理及其Fe-Ni合金电沉积工艺研究OA

Carbon fiber-reinforced metal matrix composites have been widely applied in high-end fields such as aerospace and military industries due to their advantages of lightweight and high strength.However,the carbon fiber surface is inert with a low content of oxygen-containing functional groups,resulting in poor interfacial bonding with the metal matrix.In addition,traditional processes like sintering are complicated and tend to degrade the performance of carbon fibers.To address these issues,the work aims to prepare carbon fiber Fe-Ni alloy matrix composites via surface pretreatment combined with electrodeposition,to simplify the preparation process and enhance interfacial bonding strength.The research was conducted as follows.In the pretreatment stage,leveraging the difference in thermal stability between carbon fibers and organic sizing agents,carbon fibers were heat-treated at 200-250℃.This treatment allowed the organic sizing agents to vaporize completely,while retaining the bulk structure of carbon fibers and exposing their natural groove structures,thus preliminarily increasing the hydroxyl content on the fiber surface.Subsequently,concentrated nitric acid was used for oxidation.By virtue of its strong oxidizing and acidic properties,more abundant surface grooves were constructed,and the contents of oxygen-containing functional groups(e.g.,hydroxyl and carboxyl groups)were further improved,providing sufficient active sites for the subsequent electrodeposition of Fe-Ni alloys.In the electrodeposition stage,the process parameters were first optimized by adjusting single current densities.On this basis,a dual-current density process was adopted to fabricate the composites.The surface morphology was observed through scanning electron microscopy(SEM),the surface functional groups were analyzed via X-ray photoelectron spectroscopy(XPS),and the elemental composition was determined by energy-dispersive spectroscopy(EDS).The interfacial bonding strength between the coating and carbon fibers was measured with a WDW-100 universal testing machine.For each group of carbon fiber/Fe-Ni alloy composite samples,five parallel tests were conducted,and the arithmetic mean of the five test results was taken as the final interfacial bonding strength index of the sample.The results demonstrated that the pretreatment achieved remarkable effects:the organic sizing agents on the carbon fiber surface were completely removed and the oxygen content of carbon fibers increased to 21.78%,among which hydroxyl and carboxyl groups accounted for 28.82%and 8.61%,respectively.These changes created favorable conditions for the electrodeposition of Fe-Ni alloys.In the single current density experiments,the interfacial shear strength reached a peak value of 4.71 MPa at a current density of 8 A/dm2.When the dual-current density process was employed,the interfacial shear strength was further improved to 5.17 MPa,representing an increase of 9.8%.Meanwhile,the alloy coating formed a compact and well-integrated structure.Compared with traditional methods,the direct electrodeposition process significantly simplifies the preparation steps,avoids carbon fiber damage caused by high-temperature sintering,and reduces the number of variables during the forming process.This work verifies the feasibility and optimization effect of the proposed method through concrete experimental data,providing strong technical support for the industrial application of carbon fiber/Fe-Ni alloy composites.