| With the development of society and the continuous improvement of the level of industrial informatization,the demand for high-strength conductive materials in many fields is also increasing.At present,pure copper is soft in texture and poor in strength and its application in high-strength fields is hindered.Copper-iron alloys have excellent comprehensive properties and have great application prospects.Due to the low solubility of iron in copper,the development of copper-iron alloys is limited.And the strength,electrical conductivity,plasticity and other properties of as-cast copper-iron alloy are not ideal.Therefore,the study of copper-iron composites is of great significance to promote the development of copper-iron materials.In this paper,copper particles and copper-iron mixed particles are used as raw materials for continuous extrusion process experiments.Using metallographic test,density test,hardness test,electrical conductivity test,tensile test,scanning electron microscope(SEM)performance detection method and microstructure analysis method to explore the effect of different extrusion ratio and raw material size on the continuous extrusion structure of pure copper particles and performance impact.Determine the optimal continuous extrusion scheme of copper granular material.On this basis,copper and iron particles are used as raw materials.The effects of different extrusion ratios and extrusion passes on the microstructure and properties of copper-iron composites were studied.Using 350μm Cu particles as raw material.Comparative analysis of extruded products with extrusion ratio λ of 4.6 and 8.6.It is concluded that when the extrusion ratio increases from 4.6 to 8.6,the grain size of the product decreases from 3～4μm to 2～3μm.The broken degree of oxide layer between particles increases.The bonding degree between particles is improved.The density,hardness,tensile strength,elongation and conductivity of the product have been improved.The products extruded from three different sizes of pure copper particles,Φ1mm×1.5mm Cu particles,350μm Cu particles and 61μm Cu particles were used for analysis.It is concluded that the product after extrusion with Φ1mm×1.5mm Cu particles has coarse grains,resulting in lower product performance.The product obtained by extrusion with 61μm Cu particles has insufficient inter-particle extrusion.The interface between the particles is largely unbroken,resulting in lower performance.The comprehensive performance of 350μm Cu particle extrusion products is the best.The grain size of the product is 2～3μm.Product hardness is 114.73 HV.The tensile strength of the product is 337.3MPa.Product elongation is12%.Product conductivity is 74.8%IACS.Comparative analysis of products extruded from pure copper and copper-iron mixed(15wt.%)particles.It is concluded that iron can refine copper matrix grains after adding iron particles to pure copper particles.Grain size reduced to 1～2μm.Product hardness increased to200.98 HV.Due to the increased degree of interparticle bonding and the effect of dispersion strengthening,the tensile strength increased to 485.7MPa.Product elongation is 5.2%.The resistivity increases due to the addition of iron particles and the increase in the grain boundary area.Product conductivity is reduced to 45.15%IACS.Comparative analysis of extruded copper-iron composites under different deformation degrees.It is concluded that with the increase of the deformation degree,the grain size of the copper matrix gradually decreases and the degree of fragmentation of the iron particles increases gradually.The product with repeated extrusion of Φ7mm has the greatest degree of deformation.The grain size of copper matrix is reduced to about 1μm.The iron particles are broken to about 0.5μm and dispersed on the copper matrix.Due to the increased degree of interparticle bonding and the effect of iron particle dispersion strengthening,the tensile strength increased to 512.28 MPa,the elongation was 9.6%,the hardness was 206.25 HV,but the electrical conductivity decreased to 37.84%IACS. |
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