Thermoplastic Forming of Bulk Metallic Glasses for Precision Robotics Components

Demand for novel manufacturing methods for space systems brings unique properties of bulk metallic glasses (BMG) into the spotlight. In addition to superior mechanical properties associated with enhanced reliability, BMG technology can offer new manufacturing processes that result in components with higher precision and complexity, eliminating machining and minimizing final assembly. In this project, we propose to utilize the unique thermoplastic forming (TPF) ability of BMGs to net shape high precision robotic gears. Within Phase I, we have proven feasibility of this technology. The technical objectives for Phase II is to further advance the technology to a level that allows NASA to test and use BMG gears in NASA missions. This requires high precision, repeatability, robustness, and consistency of fabricated parts. In addition, a technical focus will be on expanding the versatility of TPF-based fabrication process in terms of the range of geometries and sizes of flexsplines and the range of BMG alloys that can be used with TPF processes. Identifying the suite of BMG alloys that can be used for TPF-based molding would provide NASA with an option to select the best property combinations in terms of specific strength, ductility, wear, friction, and costs. An additional technical objective is to develop strategies to reduce friction and wear through surface finish of the molded flexsplines and fabrication of surface composites in a one processing step. The outcome of the project will be manufacturing capabilities for precision robotic components and ready-to-test flexspline gear parts with complex thin walled geometries, improved properties and dimensions suitable for Europa Lander and Kennedy Space Center and other NASA’s locations. Beyond space applications, the use of versatile thermoplastic forming processes for precision gears has a strong potential to bring cost savings for a wide range of industries that use robotic mechanisms.