Experimental Research On WEDM Machining For Meso-scale Structure Of Thin Ni-plate

With the continuous development of mechanical microminiaturization, micro manufacturing technology is playing a more and more important role in the industrial field. At present, the main processing technologies of meso-scale metal device widely used include ultra precision machining technology, UV-LIGA technology, micro electrical discharge machining technology, micro stamping technology, high energy beam machining technology and so on. Among all of these, WEDM has unique advantages in the micro two-dimensional profile machining, especially in processing of super-hard materials or complicated shapes, because it has the characteristics of non-contacting machining, low cost, large material selection rang and adaptability to small batch production. Even so, there are still no perfect processing methods and technological measures on sheet and special materials machining. So, it is of great significance to study manufacturing of meso-scale structures on thin Ni-plate with WEDM for further perfecting its processing rules and expanding application in micro fabrication.Firstly, in order to ensure the stability of the processing of0.6mm Ni-plate, i.e. wire broken never or rarely appears, some trial cuttings were carried out on the basis of the parameters of NA2400cutting3mm steel plate with Φ0.1mm Cu-wire in this paper. The processing would be stably performed by adjusting the discharge energy, liquid quantity, feedrate address and so on. Location of incision, cutting method and choice of cutting area were reasonably selected to reduce or eliminate the machining defects.Secondly, the test of5cuttings for meso-scale structures on thin Ni-plate was conducted to study the relationship between the surface quality and cutting times on the basis of stable machining. Unilateral discharge gap of each cutting was calculated by measuring surface height difference between adjacent two cuttings, and the offset values were determined according to the allowed space. Afterwards5cuttings for200μm slit were achieved:its final surface roughness could reach ra0.54μm, dimensional accuracy was higher, but the processing time was greatly extended.Finally, longer cutting time, lower processing efficiency and nearly-identical surface quality after the first3cuttings caused unnecessary waste of energy and time. Merger tests of cutting times were performed and evaluated, the results showed:the processing still could realize stable machining without broken after incorporating5cuttings to3cuttings; the final surface roughness could reach Ra0.63um, very close to the effect of5cuttings; The processed slit width decreased to150-160μm due to the reducing of the total offset, expanding application scope in the field of micro fabrication; the processing efficiency was improved, the machining time was shortened by30%. In the end, the meso-scale parts were manufactured using the developed conditions, which could satisfy the design requirements.