Preparation And Properties Of Copper Based Metallic Glass Composites With High Strength And High Conductivity

High strength and high conductivity materials are a kind of structural functional materials with excellent electrical and mechanical properties.They are widely used in power electronics,machinery,metallurgy and other fields.They are the key materials for the development of energy,electronics and other industries.In this paper,the amorphous Cu-Zr-Al(Cu₅₀Zr₄₃Al₇)alloy with good comprehensive properties and low price is used as the strengthening phase of the composites.Cu-Zn,Cu-Sn,Cu-Zn-Sn and Cu-Cr-Zr are selected as the matrix phases of the composites from the common conductive copper alloys.The spark plasma sintering(SPS)technology is used at 420?and 600 MPa,and a new type of amorphous alloy composite with high strength and high electrical conductivity was obtained by sintering the mixed powder samples.Different from the traditional copper matrix composites,this study uses the crystalline high conductivity medium strength copper alloy as the matrix phase and the amorphous high-strength copper alloy as the strengthening phase,and the powder metallurgy method is used to composite,which does not need the subsequent processing and heat treatment process,saves the tedious process,and saves energy and cost.Amorphous alloy powder was prepared by argon gas atomization method.The powder was characterized by XRD and DSC.XRD results showed that Cu-Zr-Al powder presented typical amorphous diffuse peaks.DSC curve showed that the glass transition temperature of Cu-Zr-Al amorphous alloy powder was 442?.Cu-Zr-Al amorphous alloy powder was sintered by SPS at 420?and 600 MPa.Through SEM and XRD analysis,it was found that the bulk sample was still typical amorphous structure,and no crystallization peak was found.The Cu-Cr-Zr alloy with 50%,60%,70%,75%,80%(wt.%)content was mixed with Cu-Zr-Al amorphous alloy.The SEM morphology and XRD phase composition of the alloy were characterized.SEM showed a typical two-phase distribution.The hardness,compressive strength and electrical conductivity of the composites were tested.The results showed that with the increase of amorphous content,the strength and hardness of the composites first increased and then stabilized,while the electrical conductivity decreased gradually.The fracture morphology of the composites was analyzed by SEM,and the change of fracture mode of samples with different alloy content was studied.Finally,it was determined that the comprehensive properties of the composites were the best when the content of Cu-Cr-Zr was 75%(wt.%).Cu-Zn,Cu-Sn and Cu-Zn-Sn based composites were characterized by SEM and XRD.The mechanical properties and electrical conductivity of the composites with Cu-Zn,Cu-Sn and Cu-Zn-Sn as matrix were tested and compared with those of Cu-Cr-Zr composites.The results show that the conductivity of Cu-Cr-Zr matrix composite is the highest,which is 30%IACS,and the ultimate compressive strength of Cu-Zn-Sn matrix composite is 1104 MPa.The cross-section of the samples was characterized,and the two-phase distribution and fracture mode of the composites were analyzed based on the stress-strain curves.Considering the strength,plasticity and electrical conductivity of the composites,it is determined that the crystalline Cu-Cr-Zr/amorphous Cu-Zr-Al composite with 75%content has the best mechanical and electrical properties.The conductivity is 30%IACS,and the strength is greater than 950 MPa.