Experimental Investigation of a New Grid Cathode Design Method in Electrochemical Machining

This paper focuses on the grid cathode design in electrochemical machining (ECM) in order to develop a new cathode design method for realizing a breakthrough: one cathode can produce different workpieces with different profiles. Three types of square cells, 2.5 mm × 2.5 mm, 3 mm × 3 mm, and 4 mm × 4 mm in size and three types of circular cells, with diameters of 1.5, 2.0, and 2.5 mm are utilized to construct the plane, slant, and blade grid cathode. The material of the cathode and anode is CrNi18Ti9 and the ingredients of the electrolyte are 15% NaCl and 15% NaNO3. A large number of experiments are conducted by using different grid cathodes to analyze the effects of the shape and size of the grid cell on the machining process. In addition, we compare the workpiece quality and machining error between using the grid cathode and the unitary cathode and discuss the reasons for the errors in order to obtain a better surface quality of the workpiece. Our research supports the conclusions that the grid cathode can be used to manufacture workpieces with complex shapes, the workpiece quality is better if the square cell is smaller and, for the same equivalent area, the circular grid cathode produces a better quality workpiece than the square grid cathode.