Experimental Research On Friction Assisted Nickel Electroforming With Flexible Support

Electroforming process is a kind of metal deposition technology in which the metal ions in the electroforming solution are reduced and deposited on the cathode surface by the reduction reaction occurring on the cathode surface,and then gradually stacked on the cathode surface.However,the electroforming layer obtained by the traditional electroforming process often has certain defects.Therefore,in this paper,a flexible support friction-assisted electroforming technique is used to attach a flexible support to the inner side of the anode basket,and add microbeads in the thin layer space between the flexible support and the cathode.The flexible support provides stable support while preventing free microbeads from leaking.In the electroforming process,the cathode is rotated by the decelerating motor,and the microbeads and the cathode surface are constantly friction and collision,so that the microbeads can level the cathode surface,remove the hydrogen bubble on the cathode surface,refine the grain,and thus improve the performance of the electroforming layer.Flexible support can reduce the amount of microbeads,while keeping the friction effect of microbeads constant.In the process of deposition of the electroforming layer,the flexible medium can provide buffer space,so that the surface quality and performance of the electroforming layer are consistent on the whole,and the uniformity of the electroforming layer is guaranteed.The main tasks completed are as follows:(1)Based on the friction assisted electroforming platform,a flexible support friction assisted electroforming test device was constructed.(2)The experiments of flexible support friction assisted electroforming and traditional electroforming were carried out.The surface of electroforming nickel was bright and flat,showing a similar mirror effect.The surface roughness(Ra)reached 0.057μm,the microhardness was 398.7 HV,and the tensile strength was 756.8 N/mm~2,which was greatly improved compared with traditional electroforming.Compared with traditional electroforming,the average grain size is refined to 23.7 nm.And the difference of the preferred orientation of each crystal face decreases,the difference of the growth rate of each crystal face decreases,the degree of anisotropy decreases,and the whole is more uniform.(3)Single factor impact tests were conducted on experimental parameters such as current density,cathode rotation speed,and sponge thickness.The effects of each factor on flexible support friction assisted electroforming were analyzed through surface roughness,microhardness,tensile strength,scanning electron microscopy,and X-ray diffraction.(4)The parameters of flexible support friction assisted electroforming were optimized through orthogonal experiments of current density,cathode rotation speed,and sponge elasticity.Current density,cathode rotation speed,and sponge elasticity have varying degrees of influence on the electroformed layer.The surface roughness of the electroformed layer is mainly affected by cathode rotation speed,while the mechanical properties of the electroformed layer are mainly affected by current density.