Intelligent Knowledge Based System Approach for Optimization of Design and Manufacturing Process for Wire- Electrical Discharge Machining

Wire electrical discharge machining (WEDM) is a method to cut conductive materials with a thin electrode that follows a programmed path. The electrode is a thin wire. Typical diameters range from .004" .012" (.10mm .30mm) although smaller and larger diameters are available. WEDM is a thermal machining process capable of accurately machining parts with varying hardness or complex shapes. WEDM process is based on electrical discharge machining (EDM) sparking phenomenon, utilizing the widely accepted non-contact technique of material removal. The hardness of the work piece material has no detrimental effect on the cutting speed. There is no physical contact between the wire and the part being machined. Rather, the wire is charged to a voltage very rapidly. This wire is surrounded by deionized water. When the voltage reaches the correct level, a spark jumps the gap and melts a small portion of the work piece. The deionized water cools and flushes away the small particles from the gap. This paper addresses the concept of WEDM and its parameters and development of an intelligent knowledge based system (IKBS) for WEDM in computer based concurrent engineering environment. The system links with a feature based CAD system in order to extract design data. The system is linked with databases. The machining cycle time, cost, material removal rate, and surface roughness of hole making are estimated for each selected design feature. The system provides useful information for product designers and manufacturing engineers and also advises manufacturing engineers to select optimum machining parameters.