SBIR-STTR Award

Joining is a critical, enabling technology in many industrial sectors that have problems of concern to the Department of Energy. The reliability of joints, especially welded joints, is often the limiting factor in the performance of systems in automobiles, power generators, and electronics. In the process industry, it is common to have mounting conditions where a shaft is mounted to a mill head and oftentimes a common cause of shaft failure is this very welding of the mill head to the shaft. This project will develop an innovative and highly efficient joint technology for the replacement of welded joints in shafts to mill heads. This concept involves the novel use of machinable ceramics and locking assembly joints that will eliminate current welding methods and maintain the structural integrity of the mill head and the shaft while providing improved heat-insulating characteristics. The new joint technology can be manufactured economically using current manufacturing capabilities. In Phase I, stress analysis and heat transfer computer models (finite element analysis) will be used to examine and optimize several shaft to head attachments. Additionally, computer models will be used to optimize future ceramic-metal shaft to mill head joining technology. In Phase II, the best methods for connecting shafts to heads with both ceramic and metal locking assembles will be determined. Prototype mill heads will be developed and tested to ascertain the operating characteristics of the new designs. A final design and prototype of a machinable ceramic locking assembly joint will also be developed and tested during Phase II.Commercial Applications and other Benefits as described by the awardee:These advanced concepts and approaches will improve joining technology for shafts in both military and civilian markets. Applications include the power industry, turbine blades, gas turbines, aerospace, manufacturing, electrical, rubber, food processing, process machinery and heating and cooling systems.

Joining is a critical, enabling technology in many industrial sectors that impact overall energy use. In the process industry, where it is common to mount a shaft to a mill head by welding, the weld itself is oftentimes a common cause of shaft failure. This project will develop an innovative ceramic locking assembly joint that would replace current welding methods, maintain the structural integrity of the mill head and the shaft, and provide improved insulating characteristics. In Phase I, analytical models for the mill head, ceramic shaft, and ceramic locking assembly were developed and used to design a method for joining the shaft to the mill head. The resulting ceramic locking assembly was further analyzed with thermal and stress models to improve thermal insulation capabilities. The models were further used to predict joint behavior, reliability, and lifetime. In Phase II, a ceramic locking assembly will be developed, and a prototype will be made and tested.

Commercial Applications and Other Benefits as described by the awardee:
Ceramic locking assemblies could be used in high temperature, high stress rotating equipment in the commercial aerospace market, power industry, automotive market, mining market, electrical equipment market, rubber product equipment market, food processing equipment market, turbine blades, heat equipment, cooling equipment, and the production equipment market.