Quality Water Lubrication of Special Triboceramics, Alloys and Self-Lubricating Composites

The objective of this project is to identify and demonstrate tribology materials and designs for use in advanced meso-scale steam engine expanders operating without lubricating oil. All candidate positive displacement expanders for steam engines requiretribology technology that can provide reasonable friction and wear while maintaining contact and/or close running clearances of the moving parts in a high temperature and pressure stress environment. Graphite materials and material combinations are a classof materials that have good potential for this application. The identification, evaluation, and application to graphite-based tribological systems to the design of steam expanders will be the primary focus of this work. The general approach will be tofirst implement specialized engine component tribological test apparatus. A full scale steam expander machine, of approximately 1 kW power capacity, will then be designed and tested. This approach is justified based on the complex materials, mechanical,stress, and thermal conditions encountered in steam expanders and the difficulty replicating all conditions in a more controlled manner in standard test instruments. Emphasis will be on expander mechanical configurations that have the potential to minimizethe wear and friction conditions imposed on the tribological elements of the design, such as may be available with the scroll type expander design. Steam conditions to 1000 pisg will be investigated.