Experimental Research On The EDM Electrode Manufactured By Copper Electroforming Based On La₂O₃

Electro forming is a method of producing pieces by deposition of a metal onto a mold (mandrel) which is subsequently removed. Electroforming is usually used to producing parts with precise surface details or complex-shaped components, because of its two unique features:high repetition accuracy and high repeatability precision. In the fields of aviation industry instrument industry,plastic industry and so on, electroforming has already been one of the main methods to produce precise components with alien shape. In recent years, electroforming has made prominent success in the field of Micro Electric Mechanical System. LIGA is one typical practical example, which is widely used to reproduce micro-structures with high-aspect-ratio or complicated3D shape.Due to its two main features, electroforming is very suitable for making EDM electrode, especially for EDM electrode used for machining complex cavity. However, the quality of electroformed layer directly decides the machining properties of electrode and the machining quality. Choosing appropriate basic electrolyte and corresponding additives is one of the most important methods to enhance electroforming quality. In this paper, we choose acid copper-bath as basic electrolyte and La2O3as additive, carry out copper electroforming experiment, test and analysis the electroformed copper layer. The main content is listed as follows:1. Determine the ingredients of the basic electrolyte and process parameters for electroforming. Using the surface micro morphology, surface roughness, surface micro-hardness, corrosion resistance of electroformed copper layers as criteria, carry out orthogonal test to determine the appropriate process parameters match of current density,bath temperature,PH and amount of additive Cl-2. Based on determined basic electrolyte and optimized process parameters, add different amounts of La2O3to basic electrolyte to make electroformed copper specimens. Test these specimens by instruments such as SEM to determine the relationship between surface micro morphology,surface roughness,surface micro-hardness,corrosion resistance of electroformed copper layer and amounts of3, then we can know the most appropriate amounts of La2O3, which makes the electroformed copper have best performance.3. Using electric parameters that will result in relative high electrode wear, take these specimens as EDM electrode to machine steel. Compare electrode relative wear and analysis the reasons for the results, then determine the relationship between amounts of La2O3and electrode wear.