This award supports an eighteen month Japan Society for the Promotion of Science (JSPS) Short-Term Postdoctoral Fellowship for John A. Patten at the University of North Carolina in Charlotte. He will be collaborating with Professor Wei Gao at Tohoku University in Japan. They will be undertaking research on the machining of ceramics. This will involve working on three different silicon nitride ceramics. They are a reaction bonded silicon nitride from Ceradyne, a hot isostatic press (HIP) material from Japan and a commercial HIP material from Allied Signal. All three materials behave similarly when machined, in that they have a ductile to brittle transition (with increasing depth of cut or increasing feed) yet all behave differently in terms of their machining characteristics. They will be studying the forces, tool wear, cutting edge radius measurements, finished surface roughness and then evaluating the material removed (chips) and the finished surface for signs of phase transformations using TEM and Raman Spectroscopy.
The researchers hope to determine the behavior differences for these three materials and then develop methods to exploit their differences. Ductile machining of ceramics is advantageous in that very smooth, crack free surfaces can be generated. Such surfaces are useful for many structural and also microelectronic applications. This project will offer a good opportunity to join efforts between the two countries. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. The researchers plan to publish results of the research on the web and report on the findings at scientific meetings.