FUNDAMENTAL AND APPLIED RESEARCH AND DEVELOPMENT IN METALLURGY. DEVELOPMENT OF A FABRICATION PROCESS FOR SEAMLESS TUNGSTEN TUBING. Summary Technical Report to the United States Atomic EnergyCommission for the Period July 1, 1962-June 30, 1963
A method of fabrication is being developed for highquality wrought seamless tungsten tubing in size ranges from 1.2 to 0.1 in.-OD. The process consists of extrusion of sintered powder tungsten sleeves at elevated temperatures, followed by a finishing operation by warm drawing to achieve satisfactory dimensional tolerances. Tungsten tubing in sizes between approximately 0.75 and 0.25 in. OD was extruded by the filled billet'' method. In this technique, the tungsten sleeve, which occupies a relatively small proportion of the total billet cross section, is surrounded on both outside and inside by other materials called fillems.'' After the tungsten and the filler anaterials are extruded together to form a solid round rod, the filler materials are removed either by acid pickiing or by mechanical methods. The removal of the filler material on the inside of the tubing is greatly facilitated by the use of a graphite central core, which is extruded with the billet assembly and is removed by drilling before pickling of the fillem material. Two distinct extrusion methods were nomally used: at an extrusion temperature of 1800 deg C (3272 deg F) the billet filler material was molybdenum; at 1200 deg C (2192 deg F), the filler was molybdenum in combination with low carbon steel. Tubing with superior dimensional control and surface finish was obtained at the lower extrusion temperature. The tungsten tubing in the as-extruded condition was evaluated in a limited manner. The tubing, which was shown to be fully dense and free of cracks, had considerable ductility at temperatures near 400 deg C (750 deg F). Brittle-to-ductile transition temperatures as low as 40 deg C (100 deg F) were obtained. A technique of warm drawing the extruded tungsten tubing to obtain very good surface finishes and dimensions was developed. (auth)
- Research Organization:
- Nuclear Metals, Inc., West Cocord, Mass.
- DOE Contract Number:
- AT(30-1)-2784
- NSA Number:
- NSA-17-041386
- OSTI ID:
- 4629787
- Report Number(s):
- NMI-1260
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- United States
- Language:
- English
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