Research On Turning Performance Of Particle-reinforced Polymer Matrix Composites

Due to its high hardness,high specific modulus,high strength and other properties,composite materials are widely used in defense,military,aviation industry and other fields.Composite materials can be divided into particle reinforced and fiber reinforced two types according to the type of reinforcement phase.Particle reinforced composites are widely used due to their simple preparation and low cost.Particle reinforced polymer matrix composites are one of the most prominent examples.With the development of science and technology,products in the fields of aerospace,medicine,military industry,automobile industry and other fields have higher and higher requirements on the surface quality and precision of workpiece.However,traditional methods such as injection molding and hot pressing are difficult to meet the requirements.Therefore,secondary processing methods such as turning and milling are required.The particle reinforcement phase with high strength and high hardness is distributed in the composite.On the one hand,it can improve the mechanical properties such as the strength and hardness of the material,on the other hand,it will cause problems such as poor surface quality,tool wear and high processing cost during the processing process,which reduces the processing performance of the composite.It is difficult to meet people’s requirements.At present,the research on particle-reinforced composites mainly focuses on metal matrix composites,and very little work has reported the polymer matrix composites.In this paper,copper particles reinforced polytetrafluoroethylene(Cu/PTFE)composites were tested to explore the processing properties of particle reinforced polymer matrix composites.In this paper,the mechanical properties of polytetrafluoroethylene(PTFE)and Cu/PTFE materials were compared to explore the effect of particles on the mechanical properties of composite.On this basis,the turning force signal during the turning process is collected in combination with the turning experiment.Analyze the relationship between process parameters and turning force.In order to further explore the cutting performance of Cu/PTFE composites during turning,the relationship between temperature and surface roughness during turning was analyzed.Combined with the particle reinforced composite cutting simulation model,the removal law of the composite is comprehensively analyzed.The main research contents of this paper are as follows:1)Dynamic thermomechanical analysis(DMA)of Cu/PTFE composites was performed to investigate the effect of temperature on the mechanical properties of the material.Static and dynamic mechanical experiments were carried out on PTFE and Cu/PTFE materials to explore the mechanical properties of the materials at different temperatures and strain rates.The Johnson-Cook constitutive model of the material was fitted based on the experimental data.2)Orthogonal turning experiments were carried out on Cu/PTFE composites.A range analysis was performed on the experimental results.The relationship between process parameters and cutting force was explored.Based on the simulation software ABAQUS,an equivalent homogeneous model was established to simulate the cutting process.The accuracy of the model is verified by comparing with experiments.Based on this model,the relationship between cutting force,tool angle and process parameters is further studied.3)Single factor experiments were carried out on Cu/PTFE composites to study the characteristics of temperature and surface morphology during turning.Three different forms of particle removal exist for machined surfaces.During the machining process,with the increase of temperature,the surface roughness at different feed rates showed an overall increasing trend.Combined with the theoretical calculation formula of surface roughness,the influence of process parameters is excluded.The relationship between temperature and surface roughness is further explored.4)In this paper,a microscopic multiphase model of Cu/PTFE composites was established with ABAUQS.The relationship between cutting path and particle removal law is analyzed.On this basis,it is combined with Python for secondary development.A random particle cutting simulation model was established to explore the influence of particle state and process parameters on cutting force and stress.