Development of High Strength Columbium and Tantalum Alloy Tubing
Abstract
The evaluation of the extrudability of B-66 (Cb-5V-5Mo-1Zr) and T-111 (Ta-8W-2Hf) at a reduction ratio of 7:1 was accomplished. An evacuated mild steel can was used as cladding for the extrusion billets. Both B-66 billets were extruded at 2200 deg F, using ram speeds of 275 inches per minute and 1000 inches per minute. The billet extruded at a ram speed of 275 inches per minute exhibited slight rattlesnaking for 6 inches near the nose end, with the balance of the as-extruded surface smooth and free of defects. Increasing the ram speed to 1000 inches per minute resulted in moderate rattlesnaking and circumferential cracking the entire length of the billet. The depth of the cracks was approximately .020 - .040 inches. The extrusion constant for B-66, based on the running pressure, was 78 - 84 ksi. a The initial T-111 billet was extruded at 2200 deg F and at a ram speed of 175 inches per minute. The as-extruded surface was smooth and free of defects. Increasing a the temperature to 2300 deg F and the ram speed to 1000 inches per minute resulted in slight rattlesnaking over a 6-inch length approximately 6 inches from the nose end. The balance of the extrusion was free of defects. The increase in extrusion temperature and ram speed decreased the extrusion constant for T-111 from 84 ksi at 2200 deg F to 80 Icsi at 2300 deg F. Results of the extrusion evaluation, using solid billets, indicate that the extrusion of tubular billets of B-66 and T-111 at 7:1 reduction ratios is feasible using the mild steel cladding technique. A portion of the B-66 solid rod extrusion was conditioned and after heat treatment will be gun drilled This starting tubular shape will 6e used to evaluate the hot drawing characteristics of B-66. During the next reporting period, the tube blanic extrusions will be completed and the initial processing to tubing will commence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 12, 1963
- Accession Number
- ADA397506
Entities
People
- R. W. Buckman Jr