Basic Experimental Research On Cu/ZrW₂O₈ Composite Electroforming

The low thermal expansion composite materials which are represented by composited negative thermal expansion particle have been widely used in a lot of fields such as aeronautics and astronautics,electronic packaging,precision instruments and so on.Copper has excellent conductivity,heat conduction and good molding performance which applied on many occasions.But there are few reports on the preparation of Cu/ZrW₂O₈ composites by composite electroforming.In this paper,Cu/ZrW₂O₈ composite material was prepared by ultrasonic assisted method which adopts composite electroforming technology,and the influence of the parameters of composite electroforming on the particle content in the Cu/ZrW₂O₈ composite layer was systematically studied.,the microstructure and micromorphology,micro-hardness and thermal expansion properties of the prepared Cu/ZrW₂O₈composite layers were analyzed with the aid of metallographic microscope,SEM,XRD,micro-hardness,TMA and other materials analysis instruments.The following works have been done:1.In order to produce composite materials with a low coefficient of thermal expansion,ZrW₂O₈was selected as a negative thermal expansion particle,and an ultrasonic assisted composite electroforming study device is set up,including electroforming unit,temperature control unit,circulation control unit and so on.On this basis,the experimental study of Cu/ZrW₂O₈ composite material was prepared by ultrasonic assisted composite electroforming,and discussed the influence of cathode current density,particle placement and ultrasonic power on the particle content of Cu/ZrW₂O₈composite electroforming layer.There were studied and analyzed the microstructure,micro-hardness and thermal expansion coefficient of Cu/ZrW₂O₈ composite electroforming layer with different particle content.The results showed that:It is feasible to prepare Cu/ZrW₂O₈ composite materials by composite electroforming,and the compound content of the particles can be controlled by controlling the parameters of composite electroforming.Compared with the copper layer,the Cu/ZrW₂O₈composite layer has higher micro-hardness and lower thermal expansion coefficient.2.For the produced Cu/ZrW₂O₈ composite electroforming layer,the annealing process of 150oC and 400oC was studied.The results showed that:After annealing,the density of Cu/ZrW₂O₈composite electroforming layer was increased,and the micro-hardness increased with the increase of temperature.However,the coefficient of thermal expansion was decreased first and then increased with the increase of temperature.3.In order to increase the thickness of the composite layer and increase the compound quantity of the negative thermal expansion particles,the paper proposed the solution of the composite electroforming of the batch buried sand,and by improving the electroforming process,large thickness composite materials samples were prepared.It was discussed the influence of intermittent buried sand time on Cu/ZrW₂O₈ composite electroforming layer,and analyzed the particle content,microstructure and thermal expansion of Cu/ZrW₂O₈ composite electroforming layer.The results showed that:For the composite layer,the compound content of the particles can be controlled by controlling the parameters of composite electroforming.The structure of Cu/ZrW₂O₈ composite electroforming layer has been changed,and it has the excellent performance of micro-hardness.