Experimental Research On The EDM Electrode Manufactured By Electroformed Copper-Silicon Carbide

Electrical discharge machining(EDM) is a non-traditional processing method which melts work-piece with high temperature generated by instantaneous spark discharge between positive and negative poles,the method can achieve desired size and surface quality. The materials and produce methods of tool electrode were always the key indicator of machining quality in the process of EDM. The EDM electrode should have high melting point, electrical erosion resistance and excellent electrical properties. In order to improve electric corrosion resistance of the EDM tool electrode, this article selects La2O3 as plating bath additives to produce Cu-SiC composite electrodes, and selects the sintered NdFeB permanent magnet as word-piece in the experiment.The main research and results is listed as follows:1. On the basis of analyzing the composite electroforming theory, planning out the process routes of electroforming the Cu-SiC composite electrodes. To obtain fine deposits work-piece surface roughness. A set of orthogonal test to find formula and optimal parameters was designed. The optimum parameters obtained are as follows: CuSO4 ? 5H2 O 200 g / L, H2SO4 20 g / L, H3BO3 20 g / L, NaCl 80 mg / L, SiC 35 g / L,the temperature of electroforming liquid is 30℃ and the current density is 4 A / dm2.2. With the optimum process parameters, added different amounts of lanthanum oxide to electroforming solution and study the influenced on the surface morphology、 hardness、corrosion resistance of composite electroformed layers、distribution and deposition amount of SiC particles in the composite cast layer. The results showed that add appropriate amount of lanthanum oxide to the electroforming solution would get uniform Cu-SiC in the composites, few SiC particles agglomeration was observed and surface quality of Cu-SiC composites and corrosion resistance was improved, e co-deposition of copper ions and silicon carbide was promoted. The optimum amount of lanthanum oxide is 1.5 g / L, which increased hardness of composites by 27%.3. Choose the composites as tool electrode in EDM, the results showed that electrode relative mass loss is lower to 5.7% when adding 1.5 g / L La2O3.The research results suggested that manufacturing electrode by adding the appropriate amount of lanthanum oxide to electroforming solution is feasible. It has improved the property of composites and reduced relative mass loss of tool electrode.