THE SUPERFICIAL LAYER QUALITY ALLOYING BY ELECTRO SPARK DEPOSITION METHOD

摘要

The electrical discharge mechanical machining process has been used for more than 60 years. A new type of this method, which employs the tool-electrode in the form of a rotating brush consisting of wires, employed for alloying process, has been presented. The electrode is elastically pressed against the machined surface. This modified alloying method offers the following possibilities: machining of surfaces of complex shapes, high productivity, and ease of process automation. Attention has been given to the relation between the alloying effects and machining conditions. The paper presents a brief study of electro-discharge mechanical machining with an elastic, discrete electrode. The factors causing the chemical composition, surface roughness and residual stress of superficial layer have also been taken into consideration. Attention has also been given to the relation between the material of electrode and the superficial layer chemical composition. The superficial layer obtained by electro spark deposition method using brush electrode consist of several layer. At the top, a molten and resolidified layer, called recast layer, is observed. this layer is usually present because material transfer in electro spark deposition method is mainly based on melting process of the workpiece material. In the recast layer in machining condition the mixing and diffusion of the material hot electrode and the workpart can occur.