Development Of Free Microbead Friction-Assisted Electroforming Device Based On Cathodic Composite Motion And Experimental Research

Electroforming technology is a precision special processing method based on the principle of electrodeposition.It uses metal cations to electrodeposit the surface of the core mold as a cathode to process precision parts that meet certain performance and shape requirements.Loss,no heat affected zone,high forming precision,etc.,and it is mainly used in the manufacture of metal parts that are difficult to process or costly in traditional processes,and it is also have gained important applications in aerospace,weapons,and automobiles.The current electroforming equipment realizes translation or rotation of the cathode core mold through mechanical structure,but the electroforming device that is simply translated or rotated does not have the electroforming effect on the parts with complex contours(such as the liquid rocket engine thrust chamber body).Ideal,quality and performance are flawed.In order to solve the problem of quality of electroformed layer,this paper designs a special electroforming equipment for the contoured parts of liquid rocket engine thrust chamber with complex contour based on friction assisted electroforming technology.Its main research can accommodate:(1)According to the structural characteristics of the liquid rocket engine thrust chamber reduction ratio,based on the hard particle friction assisted electroforming technology,a set of electroforming equipment for the reduction ratio is designed.Based on the research of the above-mentioned devices,in order to better study the influence of the trajectory of the cathode on the electroformed layer,the cross-mode sliding group was used as the cathode translation device,and the control system of the electroforming device was developed.The entire unit includes control system,temperature control system,electroforming circulating filtration system,liquid storage tank,electroforming tank and protective device.(2)The control system of the electroforming device includes a hardware structure and control software.The hardware structure of the electroforming device control system is realized by PC+googoltech motion control card.The software programming of the friction auxiliary electroforming device control system is completed by using visual programming software VC6.0.(3)Electrolytic nickel test with insoluble anodes shows that as the electroforming time increases the nickel ion concentration in the solution is lower and lower,the electroforming current efficiency decreases with the decrease of nickel ion concentration.Under the conditions of current density of 4A/dm~2,8A/dm~2 and 12A/dm~2,the concentration of nickel ions in the electroforming solution decreased by 22.9%,38.2%and 57.3%after 12 hours of electrodeposition test.The current efficiency is reduced to 62.2%,50.1%,and 36.3%.The current density increases,the nickel ion concentration decreases,the nickel layer grain refines,and the microhardness increases.At 8A/dm~2,12A/dm~2 current density,the microhardness increases by 20.1%and 16.1%,respectively.At the same 4A/dm~2current density,after 12 hours of electroforming test,the frictional electroforming efficiency of the free microbeads was increased by 5.3%and the hardness of the electroformed nickel layer was increased by 2.3%.