Basic Research On Free-beads-polishing-assisted Electroforming With Orbital Movement Cathode

Electroforming is a precision manufacture technology in which metal ions are deposited on acathode’s surface to manufacture the parts, it is mainly used to manufacture parts which are difficultto machine or the machine cost is too high by traditional mechanical methods. However, there are stillsome disadvantages in applications of traditional electroforming including pinholes and nodules onthe surface, uneven thickness of electroforming layer and lower electroforming velocity. As a result,the development of electroforming is restricted.In this paper basic research on free-beads-polishing-assisted electroforming with orbitalmovement cathode for precision electroforming of parts with complex structure has been studied.Combining cathode’s orbital movement with Abrasion-assisted Precision Electroforming technology,non-conductive free beads were placed between the cathode and the anode to have continuous frictionon the cathode’s surface, and then affect the electrodeposition process, which could refining grain andeliminate defects, so electroforming layer’s quality and properties was enhanced.Following are the chief works completed in this paper:1. The cathode’s orbital movement mechanism with larger orbital moving amplitude andfrequency was designed, then constructed electroforming device and free beads observing system offree-beads-polishing-assisted electroforming process with cathode’s orbital movement.2. The principle of free-beads-polishing-assisted electroforming with orbital movement cathodehas been studied, and found that the major effect of the beads for the cathode surface is sliding friction,but along with rolling friction and other beads’ impact, which have influence on metal crystallizationprocess.3. Nickel electroforming by free-beads-polishing-assisted electroforming with orbital movementcathode has been researched. The morphology, microstructure and properties of nickel depositionelectroformed with various processing parameters were studied. The results showed that comparedwith traditional electroforming, not only the surface quality with smooth and bright was observablyimproved, but also the electroforming layer’s microstructure was changed as well as the hardness andtensile strength were enhanced.4. The application researches have been studied by free-beads-polishing-assisted electroformingwith orbital movement cathode.(1) The electroforming of inlet and outlet of rocket’s cooling channelshad been conducted, the result showed that the layer with high quality near the cooling channels’ inlet and outlet was obtained using smaller free beads, lower current density and higher cathode’s orbitalmovement speed.(2) Using free-beads-polishing-assisted electroforming, the diaphragm sample withclapboard inside was successfully manufactured, furthermore the thickness of the wall is uniform andthe surface is smooth and bright.