In extreme temperatures with variable atmospheres in space exploration, traditional oil lubricants and greases are infeasible. To develop and verify the correct bearing materials/lubricants for these environments, we will use a special instrument for tribological study at extreme temperate conditions with a controlled gas atmosphere. We propose preliminary testing of one tribo-pair of advanced high temperature bearing materials (PS/PM400 sliding against BAM) that are suitable for Venusian surface conditions: PS/PM400 composite was developed by NASA scientists and it is a self-lubricating composite coating for high temperature applications up to 927˚C; boron-aluminum-magnesium (BAM - Al0.75Mg0.75B14), which is a high temperature, high wear resistance, low friction ceramic material. For lower temperature ranges, we propose to use a tribo-pair of advanced polymer bearing coatings sliding against each other for wide temperature range (cryogenic to 300˚C) applications: the coatings are based on aromatic thermosetting copolyesters (ATSP), which has demonstrated excellent tribological performance. This concept of polymer coating sliding on polymer coating yields the beneficial effects of “transfer layer”, which can efficiently reduce friction. In other words, one of the polymer coatings will work as a “pre-deposited transfer layer”, thus reducing friction. In addition, because the cosmic environment radiation, mainly a combination of protons and alpha rays, might deteriorate the bearing materials after long time service in space exploration, we will study radiation exposure effects on the bearing materials. This study will be invaluable in qualifying tribological materials for mechanical devices (e.g., drills, electric motors, bearings) for use in extended deep space missions.
Advances in understanding friction, wear, and radiation and estimation of lifetimes for NASA instruments which incorporate tribo-components (ex: drills, actuators, and reaction wheels). The tribo-pair (PS/PM400 vs BAM) will offer wide temperature range from cryogenic to Venus surface conditions. The ATSP-based polymer on polymer sliding will offer low friction and wear for space instruments from cryogenic to 300˚C. In Phase II, we will use a modified tribometer for experiments in the P/T conditions of Venus surface (485˚C and 9.3 MPa gas).
Enhanced tribological characterization of materials in energy extraction operations. Characterization of advanced bearings can inform design of tribo-components in both scientific and private space development applications. Examples of components with relevance to this proposed study include bearings, gears, actuators, and drilling equipment operating in temperature ranges from -196˚C to 600˚C.