This award supports a dissertation enhancement visit to enable Professor Albert Shih's graduate student at the University of Michigan in Ann Arbor to meet with Professor Wan-Sen Zhao at the Shanghai Jiao Tong University in China. This collaborative research project will focus on advancing the friction drilling process. Friction drilling is a novel hole-making technique used on sheet metal or thin wall casting by displacing and forming a bushing. The bushing provides the extended space for thread joining of devices. Friction drilling creates a bushing directly from the parent sheet metal in a clean, chipless process. All work-material from the hole contributes to form the bushing. In addition, no cutting fluid or lubricant is necessary, which makes the friction drilling process an environmentally friendly hole making process. Although the original patents on friction drilling have all expired, this process is still not well understood and it is little used in industry due to the lack of engineering information, such as tool geometry, tool material, and process parameter selection. This research project focuses on this need. Novel techniques will be developed to broaden the scope of applications for the friction drilling process. Two models will be developed: 1) an analytical model using the contact area and pressure and 2) a more complicated finite element modeling using ABAQUS software for modeling of work-flow with coupled large deformation, large strain, and high temperature. This method can generate a more comprehensive solution with the detailed temperature, stress, and strain distribution of the work-material.
Results of this research can be applied to the automotive, computer, and electronic assembly. Since the research is aimed at developing "green" drilling processes, it can have an impact on industry by reducing the production of waste and thus advancing environmentally benign manufacturing. The novel friction drilling can also simplify the factory production and inventory system by eliminating the expensive robotic welding machine and supplies of nuts on the shop floor. Close collaboration with Oak Ridge National Laboratory and Ford Motor Company are expected. This government-industry-university-international collaboration will aid in human resource development by exposing a graduate student to novel friction drilling process development with the aim for environmental protection.