Fabrication of Seamless Tungsten - 25 w/o Rhenium Tubing
Abstract
The development program was directed toward the establishment of extrusion and drawing techniques for tungsten - 25 W/o rhenium tubing in two sizes: 0.080-inch OD x 0.008-inch wall, and 0.250-inch OD x 0.020-inch wall. For each size, the primary extrusion is performed routinely. For the larger size, reliable techniques were developed and demonstrated for subjecting the extruded tubing to a series of moving-mandrel draws that iron the tubing to a reduction of about 30 percent. The successful application of moving-mandrel drawing and subsequent reeling for mandrel removal depends on the proper combination of mandrel material and working temperatures. In addition, the tubing must be properly conditioned by appropriate surface preparation and thermal treatment. For the smaller size, the proposed sequence is based on re-extrusion of the product of the primary extrusion. Although some apparently satisfactory tubing was obtained by re-extrusion, conditions for consistently obtaining sound tubing were not established. The billet for re-extrusion incorporates a removable core of calcium carbide within the inner molybdenum filler. This carbide core is removed chemically from the extruded tube by "acid drilling." The re-extruded tubing (OD about 0.1-inch) can be drawn with or without the inner extrusion fillers. The continuing metallurgical evaluations include some routine checks at various stages of fabrication as well as tests intended to guide the selection of anneals introduced in fabrication sequences.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1965
- Accession Number
- ADB270559
Entities
People
- A. L. Geary
- G. I. Friedman
- R. G. Jenkins
- S. Isserow