Preparation And Properties Of Copper-based Composites Reinforced With High Entropy Alloys

With the rapid development of aerospace?equipment manfacturing?electrical industry and other fields,the requirement for metal materials is increasing,also metal materials should have a varity of excellent metal material properties.The Cu-based composite material is produced in order to solve the problem that conventional method of strengthening copper can not satisfy both strength and conductivity.As a new type of alloy developed in recent years,it has the characteristics of high hardness and high temperature stability.Also because of the natural metal-metal interface with copper,high-entropy alloy is used as the reinforcement of Cu-based composites,which has broad research value.Laser 3D printing technology which is developing recent years,and it has the advantages of rapid prototyping and flexible operation.In this paper,two high entropy alloys,CuNiCrZrAg0.2 and CuNiCrZrZn0.2 were prepared by arc melting,and high entropy alloy reinforce copper matrix composites were prepared by laser 3D printing technology and powder metallurgy sintering.Various processing techniques were developed through metallography?SEM?XRD and mechanical properties and conductivity tests were conducted to investigate the effects of laser 3D printing and sintering on the microstructure and properties of the composites.The experimental results show that the FeNiCrCoMn-15wt.%composite with sintering temperature of 900? and sintering time of 6h also pre-compression before sintering has uniform composition,compact structure and best performance.The specific performance parameters:vicker hardness is 74,compression yield strength is 225MPa,conductivity is 40%IACS;Laser 3D printing process uses a power feeding rate of 14g/min,a spot diameter of 3mm,and the lap ratio is 20%,scanning speed is 600mm/min and printing power is 1400W,which the printing of bulk FeNiCrCoMn-15wt.%composite material has the best performance.Vickers hardness reaches 134.5,tensile strength reaches 381 MPa,and electrical conductivity is 35.9%IACS.The composite materials prepared by the two preparation methods have different degrees of improvement compared with the matrix.The composite material prepared by 3D printing is superior in mechanical performance,but the electrical conductivity is slightly lower than the materials prepared by power metallurgy process.