Modeling of High Speed Machining of Difficult-to-Machine Materials

Oklahoma State University, Stillwater OK

Investigators

Abstract

This grant provides funding for the development of an analytical model and experimental verification of high-speed machining (HSM) of different workmaterials. In specific, thermal modeling of shear localization in HSM will be conducted using different difficult-to-machine materials, such as titanium alloys, nickel-based superalloys, and hardened steels taking into account various heat sources (primary, preheating, and image) using the classical Jeager's stationary and moving heat source models. The onset of shear localization will be predicted based on thermo-mechanical shear instability of different workmaterials. Depending on the thermo-mechanical properties of the workmaterial and the cutting conditions, the cutting speed for the onset of shear instability will be determined. In addition to the conventional machine tools, such as a precision lathe and an NC milling machine, a high-speed spindle (Bryant) (50,000 rpm, 50 hp) will be used for conducting the high-speed machining tests. Attempts will be made to measure the temperature generated in machining under shear localized conditions using either advanced thermally sensitive paints and optical infrared techniques. Some of the difficult-to-machine materials including titanium alloys, nickel-base superalloys, and hardened steels are challenging materials in the aerospace and aircraft industries. New tool materials and tool geometries are being specifically developed to dramatically increase the productivity in machining. Fundamental knowledge on the nature of chip formation process, forces, energy consumed, tool wear can provide the basis for the implementation of this technology in industry. The PIs would interact with tool manufacturers as well as aircraft and automobile industries on this technology Development of infrastructure and training of qualified graduate and undergraduate students (including the U.S. - born , women, and minorities) can provide the human resources necessary for advancing manufactuirng technologies in the U.S. industry.