Biomimetic Nanostructured Coating for Dry Machining

This Phase II proposes to develop an innovative nanostructured coating, with a unique integration of hard phases and lubrication phases, for dry machining of austenite steels for the automotive and aerospace industries. This novel coating will be synthesized using a combination of electrostatic spray coating (ESC), chemical vapor infiltration (CVI), and plasma etching. W unique biomimetic inspired domes plus reservoirs surface morphology of the coating refreshes the surface of contact with lubricants constantly, leading to significantly reduced friction and wear. In comparison, current state of art for combining the hard phases and soft phases for dry machining is usually in layered structures, where the soft phases wear away quickly leaving only the hard phase behind. Dry machining eliminates cutting fluids and relieves environmental loading from sources. Cutting fluids, at yearly consumption of more than 100 million gallons in the United States, represents a significant health and environmental problem for the nation¿s manufacturers. The objective of this proposed work is to realize a reliable an scalable coating process for the coating to achieve dry machining with significantly extended tool life. The following explorative work will be carried out: (1) optimization of the combination of hard phases of different average sizes for controlled dimensions of the domes and reservoirs; (2) deposition of nanostructured solid lubricants dispersion: (3) optimization of plasma etching process; (4) evaluation of the coating (physica1, chemical, tribological and machining performance); and (5) design consideration for scaling up the manufacturing process for batch production. In the Phase I feasibility studies, all the proposed tasks have been completed; The technical objectives have been successfully accomplished. The desired surface morphology was achieved for integrating the hard phases and the lubricant phases. Preliminary tribological testing has demonstrated lower coefficient of friction and better resistance to wear than the industrial benchmark, a nonostructured solid lubricant coating (PVD) combing the hard phases and the soft phases in layered structure. These excellent results have solidly established the technical platform for Phase II. Upon the completion of the Phase II work, deliverables including the coating, coating system, and coated tool inserts are anticipated. The application of the coating is expected to facilitate dry machining - a green technology - by offering a 300% increase of tool life as compared to the industrial benchmark, better energy efficiency, and longer tool shelf life, further contributing to cost saving and a strengthening of the US manufacturing industries in world-wide competitive markets.