Perparation And Characterization Of Powders Metallurgy Fe-Cu Composite Material

Fe-Cu composite material with high strength and electrical conductivity was designed and prepared.Copper phase plays a role in binding phase in the whole material,and it formed a conductive network to improve the conductivity.Iron based organization for the strengthening phase.Copper has excellent electrical and thermal conductivity,and the iron based organization have excellent mechanical properties,such as strength,wear resistance.By synergistic effect,two different materials,copper and iron,are combined together.The method of vacuum hot pressing sintering has been used to prepare Fe-Cu composite materials in this paper.In the experiment,electrolytic Cu powder and Fe based pre-alloyed steel powder are mixed in a ball mill.After mixed,the powder was filled into reducing furnace.After the reduction,the powder was quickly put into the vacuum hot pressing sintering equipment for sintering Formation of liquid phase in sintering process of Cu.The best process of sintering is determined after the completion of the sintering process.Calculate the size of the conductive Cu phase and optimize the design of the material.Moreover,the Fe-Cu composites were strengthened by quenching and tempering treatment.At last,the friction and wear test of high speed current carrying was carried out,and the wear resistance and the resistance to electric ablation were tested.The morphology and structure of Fe-Cu composites were observed by OM optical microscope.The qualitative analysis of the materials after sintering and quenching and tempering was carried out by XRD.The morphology of powder,micro morphology of the material and the surface morphology after wear were analyzed by SEM.In addition,the microstructures of composites after sintering were studied by TEM.The results show that the optimal process parameters of vacuum hot press sintering are as follows.The sintering temperature is 1040 oC,the sintering holding time is 30 min,the sintering pressure is 30 MPa,the vacuum degree is 6.6×10-3Pa.At this point,the performance of Fe-Cu composites is the best.The Cu content was calculated and analyzed and control the change of Cu content.When the Cu content was 60%,the material had excellent electrical conductivity and mechanical properties,and conductivity reaches 25%IACS,and tensile strength is close to 500 MPa Quenching and tempering process parameters for the 1000 oC low temperature quenching,550 oC under repeated tempering.The tensile strength of the Fe-Cu composite is 572 MPa,and the dimples of different sizes can be seen in the fracture.The strengthening phase plays a dual diffusion strengthening in the matrix.The conductivity reaches 25%IACS.The main structure of the matrix is Cu phase,and M6 C,M23C6,MC type carbide on Fe matrix.The friction and wear behavior of Fe-Cu composites was studied under different load,sliding speed and current.Under the small load,the wear of the material is mainly abrasive wear.The wear mechanism is abrasive wear at tiny load and low speed.The wear mechanism of material under high current and high speed is a mixture of abrasive wear and adhesive wear.