Injection mold discharge machining introduction

Injection mold discharge machining introduction

Discharge machining is often used in machining the core of plastic mold. The discharge machining method is an excellent machining method that can simply process the shape of hardened steel. It is also suitable for the machining of precise shapes and 3D surfaces.

Discharge processing, usually make electrode, so that it is processed with the object (workpiece) confrontation, in the two sides apply different potential, in the processing oil electrode gradually close to, with the heat energy generated by the high temperature arc discharge, melting part of the workpiece and rapid decomposition processing method.

The electrodes are moved up and down through the servo motor to restart the next discharge.

The surface of the workpiece is very rough because of the numerous crater traces. In addition, in the case of steel, the carbon components in the processing oil impregnated into the melted steel, which became martensite (crystalline structure during quenching) with a large amount of carbon, residual stress, and also produced numerous tiny cracks (microcracks).

A few microns thick and unstable hardening layer is formed on the surface after discharge machining. However, if the surface after discharge machining is not carefully grinded with grinding wheel or whetstone, and the hardening layer is not removed, the micro cracks will gradually increase after the continuous processing of injection molding, and sometimes lead to the bad occurrence of the fracture of the mold parts.