9500420 Ferreira Structural ceramics materials can be used in engines, electronics, tooling or other applications where high temperature performance, strength to weight ratios, and wear or corrosion resistance are important. Today the use of structural ceramics is limited, in part, because they are very difficult and costly to process into useful products. This project will provide a fundamental understanding of a new process called rotary ultrasonic machining (RUM), that promises to reduce the processing time, and hence cost, without imparting sub-surface damage that would limit the life and reliability of structural ceramic components. RUM uses ultrasonic vibration normal to a surface that is being generated to enhance material removal by fracture, rather than by plastic deformation, in brittle hard materials. This project examines the fundamental material removal mechanisms in the RUM process, that will be used to design a first generation RUM machining system. There are also fundamental integration issues in the design of such a machine, for example, the use of adaptive control to maintain nominal normal pressure while machining. This fundamental understanding and experimental work on RUM has the potential to provide a cost effective way to process structural ceramics. This impact of this new knowledge will be longer life for mechanical components subjected to moving contact, or higher density and lower cost electronic storage devices made from structural ceramic. ***
