This Small Business Innovation Research (SBIR) Phase II research project develops a temperature-adaptive nanoparticles-based solid lubricant coating (ZnO and MoS2 and their metastable forms) on textured cBN/TiN for hard turning and dry machining applications. The uniquely coated tool inserts are able to constantly release the lubricants out of reservoirs on the textured cBN/TiN surface. Currently available solid lubricant coatings do not offer temperature-adaptive properties and are NOT suitable for hard turning applications. Hard turning can offer manufacturers large cost savings compared to grinding. However, the achievable surface finish is critical. The preliminary results indicate that the proposed solid lubricant coating will enhance hard turning surface finish and provide greater consistency. In addition, both environmental and competitive cost issues are causing manufacturers to migrate toward dry machining. Solid lubricant coatings can both improve surface finish and extend the tool life in dry machining applications by lowering the friction at the interface between the tool and the workpiece. Commercially available solid lubricants are primarily configured in layered structures. As wear progresses, the lubrication layer wears away and leaves the hard layer behind. Thus, the proposed novel configuration that provides temperature adaptability while also offering continuous long lasting lubrication has great potential.
The proposed research is an excellent example of adding value to industrial products from the investment in nano science and engineering. The project will provide improved understanding of how the tribo-chemistry of nanoparticle coatings can offer temperature adaptive properties and affect machining performance. Also, it will provide insights regarding the micro tribology along the boundary of the particles and binder(s). The primary application of the coating will be for cutting tools in hard turning and dry machining. These are very important and growing commercial markets. Additional markets could be for rotating machinery, dies and molds, and other wear parts. The successful development of the proposed coating will help reduce environmental waste and contaminants from the usage of coolants. The disposal of both the used cutting fluid and the contaminated metal chips that were removed during the cutting process is becoming harder and more costly. The cost of the coolant has been widely estimated as contributing over 15% of a typical part.s machining costs. The project will help facilitate the adoption of high speed machining techniques, which is considered a key factor for the United States maintaining its manufacturing base in the face of strong competition from low labor rate countries.
