A process that is undergoing development would be used to mass-produce textured polycrystalline rods of a terbium/dysprosium alloy for cryogenic magnetostrictive actuators. The rolling-and-heat-treatment process described in the preceding article yields a high degree of crystal orientation, but is suitable for small batches only. The developmental process is expected to be inexpensive to provide greater uniformity in larger batches in a mass-production setting.
The process exploits an established coextrusion technique in which a tube is filled with a material, then the tube and its contents are redrawn to a smaller diameter. The uniform stretch of the tube and its contents yields a high degree of orientation of crystals along the axis of the tube.
First, the unoriented polycrystalline Tb/Dy is encased in a tube of 316L stainless steel. Then the filled tube is drawn through a die sized to increase the length of the tube by a factor of 4. Finally, the tube is split to remove the polycrystalline Tb/Dy rod. The degree of parallel alignment and long-axis orientation of the crystals in the drawn rod is sufficient for an effective magnetostrictive actuator.
This work was done by Robert Chave, Jennifer Dooley, Brent Fultz, and Marius Birsan of Caltech for NASA's Jet Propulsion Laboratory.
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to
Technology Reporting Office
JPL
Mail Stop 122-116
4800 Oak Grove Drive
Pasadena, CA 91109
(818) 354-2240
Refer to NPO-20277
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Extruding Tb/Dy alloy magnetostrictive actuators
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Overview
The document outlines a technical support package from NASA's Jet Propulsion Laboratory (JPL) detailing a novel process for mass-producing textured polycrystalline rods of a terbium/dysprosium (Tb/Dy) alloy, which are crucial for cryogenic magnetostrictive actuators. The invention, credited to Marius Birsan, Robert G. Chave, Jennifer A. Dooley, and Brent T. Fultz, addresses the need for a low-cost and consistent method to produce large quantities of highly oriented Tb/Dy material.
The existing rolling-and-heat-treatment process, while effective in achieving a high degree of crystal orientation, is limited to small batch production. The new method leverages an established coextrusion technique, where the unoriented polycrystalline Tb/Dy is encased in a tube made of 316L stainless steel. This tube is then drawn through a die, increasing its length by a factor of four. This process results in a uniform stretch that aligns the crystals along the tube's axis, enhancing the material's properties for actuator applications.
The document emphasizes the novelty of this approach, highlighting its ability to produce large quantities of oriented Tb/Dy at a lower cost while maintaining high consistency. The method not only improves production efficiency but also ensures that the resulting material meets the performance requirements for effective magnetostrictive actuators.
The technical disclosure includes a clear problem statement, identifying the motivation behind the development as the need for a reliable and economical production method for actuator materials. The solution is succinctly described, detailing the steps involved in encasing, drawing, and splitting the tube to obtain the desired oriented polycrystalline rods.
In summary, this document presents a significant advancement in the production of Tb/Dy alloys for cryogenic applications, showcasing JPL's commitment to innovation in aerospace technology. The process is expected to facilitate the mass production of high-quality materials, ultimately contributing to the development of more efficient and reliable magnetostrictive actuators for various applications. For inquiries regarding commercial use, the document provides contact information for the Technology Reporting Office at JPL.
