This article discusses recent developments in high-temperature electrostatic levitation technology for containerless processing of metals and alloys. Presented is the first demonstration of an electrostatic levitation technology which can levitate metals and alloys (2-4 mm diam spheres) in vacuum and of superheating-undercooling-recalescence cycles which can be repeated while maintaining good positioning stability. The electrostatic levitator (ESL) has several important advantages over the electromagnetic levitator. Most important is the wide range of sample temperature which can be achieved without affecting levitation. This article also describes the general architecture of the levitator, electrode design, position control hardware and software, sample heating, charging, and preparation methods, and operational procedures. Particular emphasis is given to sample charging by photoelectric and thermionic emission. While this ESL is more oriented toward ground-based operation, an extension to microgravity applications is also addressed briefly. The system performance was demonstrated by showing multiple superheating-undercooling-recalescence cycles in a zirconium sample ( T, = 2 128 K) . This levitator, when fully matured, will be a valuable tool both in Earth-based and space-based laboratories for the study of thermophysical properties of undercooled liquids, nucleation kinetics, the creation of metastable phases, and access to a wide range of materials with novel properties.

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Lord Corporation has developed glycol-based magnetorheological (MR) fluids for use in applications such as engine mounts and bushings, in which the MR fluid will contact rubber or other oil-sensitive elastomers. Prototype MR fluid engine mounts were designed with either a simple MR valve or an MR valve in combination with an inertia track. The mounts were filled with glycol MR fluids containing either 22% or 36% iron by volume, and the mounts’ dynamic responses were measured. The mounts displayed large changes in dynamic stiffness and damping that were controllable by changing the strength of the magnetic field.