Basic Experimental Research On Composite Electroforming Of Cu/ZrW₂O₈ And Electroforming Fe-Ni Alloy

The low thermal expansion alloy which is represented by the Fe-Ni alloy and negative thermal expansion particle reinforced metal matrix composite materials have been widely used in a lot of fields such as the aerospace,military project and the precision meter.In this paper,the Fe-Ni alloy prepared by electroforming assisted with mechanical polishing.The influence of the current density and the rotate speed of the cathode on the composition of the electroforming layer have been analyzed.In order to research the composite electroforming of Cu-ZrW₂O₈ in depth,the traditional composite electroforming and flushing sand composite electroforming have been applied in the paper.In this paper,the influence of electrodeposition parameters on the particle content in the composite materials was focused.The effects of particle content on the microstructure and physical properties of composite materials including CTE and microhardness were also evaluated by the SEM,XRD and TMA.At present,the preparation of Cu/ZrW₂O₈ composite materials by the composite electroforming has fewly been reported.The following works have been done:1.The fundamental experimental study of the Fe-Ni alloy electroforming assisted with mechanical polishing of the rotating cathode has been conducted.The influence of the process parameters e.g.the current density and the rotate speed of the cathode on the composition,and the property of the electroforming layer have been analyzed.The results showed that mechanical polishing can significantly improve the Fe content and the properties of the Fe-Ni layer.At the same time,current density and the rotate speed of the cathode can significantly influence the composition of Fe-Ni alloy layer.2.The fundamental experimental study of the traditional Cu-ZrW₂O₈ composite electroforming has been conducted and the influence of current density,particle concentration and bath temperature on the particle content in the Cu/ZrW₂O₈ composite coatings was studied.The morphology,microhardness and CTE of Cu/ZrW₂O₈ composites coatings with different content of particles prepared by traditional composite electroforming were evaluated.The experiments' results indicated that both the current density and the particle concentration play a major role in the particle content in the Cu-ZrW₂O₈ composite coatings prepared by traditional composite electroforming.Compared with the pure copper,the Cu/ZrW₂O₈ composite electroforming layer has higher hardness,lower thermal expansion coefficient.3.The fundamental experimental study of the flushing sand Cu-ZrW₂O₈ composite electroforming based on the sediment co-electrodeposition has been carried out.An experimental system of the flushing sand Cu-ZrW₂O₈ composite electroforming has been designed and structured,which is composed of the electrodeposition unit,the time controlling unit,the temperature controlling unit and cycle unit.The Cu/ZrW₂O₈ composite samples with different particle content were fabricated by changing the composite electroforming parameters.The influence of electrodeposition parameters on the particle content in the composite materials was focused.The effects of particle content on the physical properties of composite materials including morphology,microstructure,CTE and microhardness were also evaluated.The test results show that the flushing sand composite electroforming can significantly improve the particle content in the Cu/ZrW₂O₈ coatings and the crystal of Cu changed.The particle content in the Cu/ZrW₂O₈ coatings and the microstructure of the Cu had an impact on the microhardness and the thermal expansion of the Cu/ZrW₂O₈ composite coatings.