Research On Mask Electrochemical Process For Preparing Surface Textured Cold Pressing Molds

Surface texture refers to the micro-or sub-millimeter-level microstructures(such as micropits or microgrooves)with specific size,shape and regular arrangement that are processed on the material surface,which can obtain surfaces with specific functions.Studies have shown that altering the surface texture can have a significant impact on reducing frictional forces,minimizing wear,and optimizing heat transfer and fluid motion state,and has found broad applications MEMS,aerospace,communication and electronics,precision machinery,biology,medical technology,and other related fields.At present,there are various processing technologies that can construct surface texture,such as femtosecond laser processing,abrasive jet processing,surface shot peening technology,microelectrical discharge machining,ion etching processing and precision mechanical processing technology.However,these methods are difficult to meet the requirements of high efficiency,large batch,low cost,energy saving and material saving for industrial production at the same time,which limits the application of surface texture in industrial fields.In view of the problems existing in the traditional surface texture processing methods,a high-efficiency and low-cost surface texture processing methodsurface texture cold forming process is studied.However,this micro-convex structure not only requires high strength,high stiffness,high precision,and other properties that traditional embossing molds possess,but also places high demands on the size and uniformity of the structure,making manufacturing difficult.To solve this problem,a penetrating mask electrochemical process is proposed to prepare micro-column molds,which solves the problem of processing microcolumn array structures on the surface of alloy steel mold materials,and improves the processing efficiency of cold forming mold surface texture and reduces the processing cost.The following presents the key research contents and outcomes of this paper:(1)The basic principle of mask electrochemistry is analyzed,the corrosion mechanism of electrode/solution interface is introduced,and the formation process of electrode polarization and passivation film is expounded.(2)In order to prepare the insulating mask,the simplified lithography process design and equipment construction for alloy steel were completed,and the influence of polishing accuracy,pre-drying time and exposure time on the molding quality of the mask was studied through single-factor experiments,and the insulating mask with better morphology and excellent quality was prepared on the surface of alloy steel through optimized photolithography process parameters.(3)The design and construction of electrolysis experimental system are completed.The adjustment of voltage frequency duty cycle and data acquisition during experiment process as well as electrolyte flow rate control are realized.(4)Through orthogonal experiments the effects of electrochemical parameters on micro-column height lateral corrosion height standard deviation etching concentration were analyzed.Then using gray correlation analysis obtained comprehensive index(height standard deviation and etching concentration)best process parameters prepared an average height of 54.691 um top average diameter 66.248 um height uniformity better(standard deviation1.379um)taper small(etching factor 0.818)micro-column array structure.(5)Through cold pressing test verified feasibility of cold pressing mold.The test showed that when load was 15000 N excellent morphology depth 44.7um surface texture could be obtained.And through the life test,it is verified that the microcolumn array prepared by mask electrochemical process has sufficient stiffness and strength.