Basic Research On Uniformity Of Cathode Deposition In Electroforming

Electroforming is a nontraditional machining technology in which a metallic part is produced bythe electrodeposition of metal ions onto a cathode surface. It has many advantages including excellentrepetitive accuracy and high fidelity of shape reproduction from the mandrel, etc. Now it has beensuccessfully employed in the fields of precision molding, aviation, aerospace, micro-machining andotherwise. However, in traditional electroforming process there are still some disadvantages that aredifficult to overcome, such as the long processing time, the poor metal distribution, some defaultsemerging in deposition layers and so on. As a result, the development of electroforming is seriouslyrestricted.To solve the problem of poor metal distribution in complex rotary part electroforming, this articlefurther study on electroforming process characteristics and theory of electrodeposition and the electricfield, then research a new method for anode design to improve thickness uniformity of the depositedlayer. Finally, a typically complex rotary electroformed part–analog-simulated sample, isexperimental verified. The study details are as the following:(1) According to the large scale complex rotary part electroforming, a new optimization methodbased on finite element analysis for anode design is proposed. Firstly a simple anode is used toestablish the initial model, so as to analyze the cathode electric field intensity distribution. To solvethe problem of abnormal electric field in a small area, an auxiliary electrode which is optimized isintroduced. In the anode contour optimization process, the adjustment quantity of anode control pointsis associated with the field intensity of cathode nodes, and the anode profile is adjusted according tothe normal direction of cathode nodes. With this method, the anode is designed for electroforming anozzle simulating part and the results shows that the current density ratio of maximum to minimum oncathode surface decreases from1.96to1.08.(2)Design and build the test device for electroforming nozzle simulating part. Then electroformingtest is done, and the results are analyzed. It shows that the method of anode design is effective.