Nano-Diamond Coated Cutting Tools: Modeling Tool Geometry Effects

University Of Alabama Tuscaloosa, Tuscaloosa AL

Investigators

Abstract

The objective of this research is to renovate the designs of nanostructured diamond (nano-diamond) coated cutting tools through fundamental studies of tool geometry effects. Ultrahard, well-adherent and smooth nano-diamond coatings have a potential to revolutionize the coated tooling technology to meet modern machining challenges. How the tool geometry affects diamond coated tool performance in machining, however, is least understood because of the interwoven effects of both the diamond deposition and cutting processes. The research approach includes experimental investigations and computational modeling of deposition residual stresses using nanoindentation, coating-substrate adhesion using bulk indentation, cutting stresses and temperatures of diamond coated tools inherited with coating attributes using two-dimensional orthogonal machining, and coating tool failures using three-dimensional machining. The subjects will be integratively studied centered on variable tool geometry including micro- and macro-features such as the cutting edge radius and nose angle. The connections between the tool geometry, coating delamination and tool life, correlated with the thermomechanical evolution of the coated tools from deposition to machining, will guide optimal designs of nano-diamond coated tools. This research will directly benefit society by advancement of cutting tool technology that will strengthen the national manufacturers in global competition. Collaborated with a tool maker, a diamond coater, and tool users from automotive industry, this research offers channels for efficient designs of nano-diamond coated tools tailored to specific machining tasks. In addition, the new knowledge of diamond coating tool behavior in machining will be transformed into development of nano-diamond coated drills and other complex-shape tooling, which are critically needed in the manufacturing industry. Further societal impacts of this research include undergraduate research by underrepresented-group students, who will also coordinate broad research dissemination. In addition, this research will reach out to the community through project participation by machine tool technology students from two-year college programs.