1. Metallographic structure and elemental composition of the workpiece material Due to the discharge of the electric spark, the metallographic structure of the surface layer of the workpiece material changes significantly, forming a discontinuous, uneven thickness of the metamorphic layer. It is related to the workpiece material, wire material, pulse power and working fluid.
After metallographic analysis, large austenite remains in the metamorphic layer. When using molybdenum wire electrode and carbon-containing working solution, the content of molybdenum and carbon in the metamorphic layer is greatly increased by spectral analysis and electron probe detection; and the working solution using copper wire electrode and deionized water is used. At the time, it was found that the content of copper in the metamorphic layer increased without carburization.