Hybrid Electrical Machining of Polymer Composites

To address the Air Force need for an electrical discharge machining (EDM) hole-drilling process in military aircraft structures, Physical Optics Corporation (POC) proposes to develop a new Hybrid Electrical Machining of Polymer Composites (HEM-POC) technology. This proposed technology is based on the combination of near-dry electrical discharge machining and non-equilibrium plasma treatment. The innovation in the tool design will enable the HEM-POC technology process to drill holes in carbon-polymer composites despite their non-conductivity, which is required for the conventional EDM process. As a result, this technology offers a high material removal rate, ability to drill large-diameter holes with perfect hole roundness, and a wide range of types and thicknesses of the processed material, which directly addresses the Air Force requirements for drilling of holes in military aircraft structures. In Phase I, POC will demonstrate the feasibility of HEM-POC technology by building a prototype tool and drilling composite materials of varied thicknesses; perform initial testing using ASTM methods; and provide initial cost estimates for the system and consumable items. In Phase II POC plans to develop the HEM-POC portable, handheld device prototype capable of integration with drills and location drilling systems, and demonstrate it in a production-representative environment and production-representative structures. BENEFIT: Meeting technical parameters required by the U.S. Air Force for electrical discharge machining of the composite materials will allow POC to initiate HEM-POC technology development for specific implementations in current and future military projects. Military applications of the HEM-POC technology will include the machining, specifically, hole drilling, in military aircraft composite structures. The HEM-POC technology can be incorporated by the U.S. Air Force into the robotic assembly systems as a compact, lightweight machining tool with low material degradation. Anticipated marketable commercial applications of the proposed HEM-POC technology include polymer machining, composite structures drilling, and non-conductive materials (glass, ceramics, polymers) micro-machining.