Study On Surface Texture Design And Cutting Performance Of Carbon Fiber Prepreg Cutting Tool

Forging composite molding method is a new rapid prototyping technology for carbon fiber parts,which has the advantages of simple process,high molding efficiency and being able to manufacture complex shape.High efficiency cutting of prepreg is the key of forging composite molding method,but the prepreg cutting object contains both brittle high hard carbon fiber and viscous epoxy resin matrix.The cutting environment becomes more complex under the synergistic action of cutting force field between tool and carbon fiber,flow field between tool and epoxy resin,and temperature field caused by friction between tool and carbon fiber.Therefore,in order to solve the problems of high cutting force and fast wear in the cutting process of carbon fiber,the application of textured tool in the cutting process of carbon fiber prepreg is proposed in this paper.Firstly,the shortening process of carbon fiber tow was studied.The performance parameters such as friction coefficient,elongation at break,maximum cutting force and cutting work in the cutting process were deduced by means of cutting force curve and mechanical analysis.The cutting process of carbon fiber tow in both dry and prepreg condition was compared and the cutting mechanism was revealed.The effect of epoxy resin on cutting performance was found.Secondly,the flow behavior of epoxy resin on the textured tool surface was simulated and experimentally studied.The influence of groove texture parameters on the lubrication performance of epoxy resin was evaluated by the values of driven pressure integral and total pressure integral,and groove parameters were optimized.The feasibility of the simulation model was verified by experiments of cutting epoxy resin with the tool.The optimized results have reference significance for the actual cutting process.Thirdly,according to the simulation results,the experiment of cutting carbon fiber with single groove texture tool was carried out.The influence of the grooves on the cutting process of carbon fiber and the serrations on the cutting edge were compared and analyzed.The dynamic pressure lubrication effect of the grooves on the epoxy resin and the micro-cutting effect of the serrations on the cutting edge were found.Under the synergistic action of the groove texture on the side and the serrations on the cutting edge,the cutting force and cutting work are greatly reduced.Finally,the mixed groove texture was designed and manufactured based on the action mechanism of single groove texture,and the influence of the mixed texture tool on the cutting performance was analyzed.It is found that the hybrid textures of 90°/0° and ±45° can further improve the cutting performance of carbon fiber prepreg under the synergistic and complementary effects.Combined with friction test and wettability test,the action mechanism of hybrid texture was further verified.