Final Report Summary - SUSTAIN-MS (Sustainable design of manufacturing systems)
Material processing technology was positioned in the SUSTAIN-MS context through the industry driven demand for the elimination of mineral oil based metalworking fluids and the implementation of advanced cooling and lubrication techniques. The project focused on exploring the performance of cryogenic cooling (using liquid nitrogen) and minimum quantity lubrication (using biodegradable oils). Both essentially different cooling and lubrication techniques have different and largely unknown effects on the performance of machining. The socio-economic impacts of considered technologies were evaluated in terms of machine-tool usage costs, labour, cooling lubrication costs, energy expenditure and waste management. The impacts of technologies on energy use, global warming potential, water use, acidification, solid waste and soil use were assessed and compared in a life cycle perspective. Cryogenic machining is economically viable for high-performance manufacturing of advanced materials. However, there is a relatively high energy embedded in the liquefaction of nitrogen. Minimum quantity lubrication has the highest potential for future implementation in high-performance manufacturing if the tribo-chemical properties of lubricants are enhanced. There is a crucial need to design and develop nano-based lubrication systems. These activities are already underway. In this respect, the continuation of SUSTAIN-MS will be achieved. The impacts are foreseen in better work environment, lower ecological burden, higher technological edge, and new business opportunities.
The dynamics in a machining system is governed by stiffness and damping in both the machining process and the machine tool structure. The investigation of machining dynamics, hence, included the entire manufacturing system, and not only the process, as a separate entity. The concept of an integrated identification of a manufacturing system included tracking the intensity of interaction between the process and the machine tool structure. Identification of this interaction was not separated from the closed loop. It was shown that the process-machine interaction could be quantified by the operational damping ratio, which captures real operating conditions. The conducted research proved viability for consideration of the manufacturing system as a black box, due to the nonlinear and stochastic nature of machining system dynamics. The investigation was based upon measuring sound pressure emitted by the process and the machine tool structure. This identification scheme will be used to control the dynamic behaviour of a machine tool during its interaction with the machining process by adjusting dynamic stiffness of the machine tool at structural joints. Such joint are currently being developed within NMP 2010-1 Plug and Produce for Adaptive Control, ensuring tangible impacts in the period of three years.