Technology Development And Performance Research Of High Conductivity Copper Matrix Composite Materials

Copper is the most widely used transmission medium,but its poor mechanical properties will limit its use in some scenarios.Therefore,it is of great significance to develop a new material that can not only retain the electrical conductivity of pure copper,but also improve its strength.Copper-based graphene material is a composite material with broad research prospects.Due to the unique properties of graphene,It not only improves the overall electrical conductivity of the material but also improves the strength of the material.In this thesis,multi-layer graphene copper sheets are prepared by rolling and compounding.Since graphene copper foil is a flexible material,it is difficult to directly carry out rolling and compounding.To this end,a wrapper was designed.The multilayer graphene copper foil was put into the wrapper and sealed to prevent oxidation during the experiment.layer graphene copper plate sample.In order to study the effect of rolling temperature on the interlayer effect of multilayer graphene copper foil,several sets of experiments were carried out at different rolling temperatures.The experimental results show that higher rolling temperature is more conducive to the composite of graphene copper foil.Several groups of experiments with different rolling reduction ratios were carried out at a rolling temperature of 500 °C.The results of comparative experiments found that with the increase of rolling reduction ratio,the tensile strength of multi-layer graphene copper sheets continued to increase,and the extension The rolling reduction rate gradually decreased,while the interlayer bonding strength increased with the increase of the rolling reduction rate.The study also found that the electrical conductivity of the multi-layer graphene copper plate formed by rolling composite has a 13% IACS improvement compared with the initial state.However,its bonding strength did not meet expectations.Using a scanning electron microscope,it was obvious that there was a large area of delamination near the fracture.In order to further improve the interlayer bonding strength of the multilayer graphene copper plate,the sample after initial rolling Secondary rolling was performed.The influence of different annealing temperatures on the conductivity of the multilayer graphene copper plate after the second rolling was also studied.The experiment compared the change of the conductivity of the sample at the annealing temperature of100-1000 °C.When the annealing temperature was lower than 300 °C,The conductivity of the multilayer graphene copper foil will increase with the increase of the annealing temperature.When the annealing temperature is higher than 300 °C,the opposite will happen,and the conductivity will decrease with the increase of the annealing temperature.Therefore,the optimum annealing temperature is 300 °C.Using a scanning electron microscope to observe the morphology of the tensile fracture,it can be known that the fine voids produced by plastic deformation inside the graphene copper plate undergo nucleation,growth,aggregation,and finally connect to form larger voids,causing fracture and leaving Dense dimples,and with the continuous increase of rolling reduction,the size of dimples becomes smaller,indicating that the bonding strength of multilayer graphene copper foil increases.The RD-ND surface of the multilayer graphene copper sheet was also characterized by an optical microscope.From the metallographic diagram,it can be observed that with the increase of the rolling reduction rate,the graphene copper foil has interlayer fractures,and the fragments formed after the fracture Will be interspersed between adjacent layers to form a tighter composite effect.