Performance evaluation of extrusion die surface modified by electro-spark deposition

The electro-spark deposition (ESD) processing method is a kind of the electric discharge machining method. It is a method of generating not the processing on a liquid inside but the spark discharge in the atmosphere, and stiffening and coating the surface of the metallic substrate with the deposition of the electrode material. In this research, the surface modification on the extrusion die bearing by the ESD processing method is tried, and the performance is evaluated. In addition, it is investigated the correlation between the abrasion of the electrical discharge coating layer and the surface properties of hot-extruded 5056 high strength aluminum alloy. As a result, it has been understood that the ESD processing of the super-hard alloy whose WC, TiC, and Co are principal ingredients is effective in the extension at the tool life and the prevention of the tearing (crack) of the extrusion material.