Preparation And Properties Of High Strength And High Conductivity Copper-based Amorphous Alloy Composites

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 industrial fields,and are the key materials for the development of energy and electronic information industries.In this paper,Cu₅₀Zr₄₃Al₇ amorphous alloy is used as the base material.The composite bulk sample is prepared by electroless copper plating and doping process using spark plasma sintering（SPS）to improve the conductivity and plasticity.And a new amorphous alloy composite material with high-strength and high-electrical conductivity has been obtained.Different from conventional copper-based composites,ultrahigh-strength amorphous alloy powder particles are used herein as starting material.The process route for the preparation of structural functional materials by sintering of amorphous alloy/crystalline metal Cu composite powder was proposed for the first time.The amorphous alloy powders were prepared by argon atomization method and were characterized by XRD and DSC.The results show that the Cu Zr Al amorphous alloy powders were successfully prepared.Amorphous bulk samples were prepared by SPS process at different temperatures and pressures.The density,hardness and electrical conductivity were tested.The morphology and phase composition were characterized by using SEM and XRD,respectively.When the sintering temperature was 420°C and the sintering pressure was 300 MPa,the bulk amorphous had a completely amorphous structure and the best performance.Using the electroless plating method,crystal Cu was introduced into the surface of the amorphous alloy powders,and the optimum process parameters of the electroless copper plating of the amorphous alloy were determined by adjusting the process parameters of electroless copper plating on the surface of the amorphous alloy.The thickness and distribution uniformity of the electroless copper plating layer were characterized by SEM and EDS,and the formation of side reaction products such as Cu2 O were not found,indicating that no impurity particles were introduced during the electroless plating.Amorphous Cu₅₀Zr₄₃Al₇/Cu composites were prepared by adding different mass fractions of copper powders to the amorphous powders of electroless copper plating and unelectroless copper plating.After performance comparison,in the case of the same copper content,the bulk amorphous composite samples sintered by electroless copper plating have higher conductivity and ductility,while the compressive strength did not change significantly.When the copper content is 40 wt.%,the bulk amorphous composite exhibited the best overall performance.Furthermore,based on the addition of 40 wt.% copper content,the effect of the particle size of amorphous powder on the properties of the composite was researched.The results showed that when the powder particle size is below 15 μm,the prepared composite material has the optimum overall performance,the compressive strength can reach 721 MPa,and the compression strain is 13%,and the electrical conductivity reaches 35.02 %IACS.The bonding,element distribution and elemental interdiffusion at the amorphous/crystal interface were analyzed by TEM and EDS.The results showed that a diffusion amorphous layer and a Cu crystal gradient diffusion layer were formed at the interface of the prepared composite,and the reasons for the formation of the amorphous layer and the diffusion layer were analyzed.It is proved that the amorphous/crystal two-phase combination is not a simple mechanical bond,but a diffusion phenomenon.