Description: 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.

Benefits: Development of novel manufacturing processes for structures with superior mechanical properties has long been identified as one of the critical needs for NASA. In this project, we focus on forming precise robotics components with thin walled structures and high dimensional accuracy using bulk metallic glasses (BMGs). BMG robotics components are highly attractive for use at low temperature and harsh environments, such as Europa mission, due to improved mechanical properties and ability to operate unlubricated. Such BMG gears can also be used in robotics arms at Kennedy Space center, Goddard Space Flight Center and other NASA's locations. Beyond robotics, BMG technology is also attractive for small satellites and pressure vessels and other structural space applications.

Combining the properties of best structural metals with the processability of thermoplastics brings unique opportunities to robotics, aerospace, defense, automotive and biomedical industries. Specific applications that we are addressing in this NASA Phase II project include precision robotics components that outside space can be used for industrial and consumer applications. Miniaturization of robotics equipment is an important trend in medical and defense applications and thermoplastic forming of BMGs is uniquely suited for this.