HIGH ENERGY RATE EXTRUSION.
Abstract
Thin structural shapes can now be produced by high velocity extrusion equipment. Tooling, dies, die coatings, lubricants and general processing parameters have been developed to produce titanium alloy, stainless steel, low alloy steel and refractory metal alloy shapes. Extruded Tee sections, 2 inches by 1 inch by .050 inches thick, have been made in lengths of 10 feet from titanium-6Al-4V, AISI 4340 and 304 stainless steel. These extrusions have uniform surfaces (100 rms or better) and good dimensional tolerances (=.005 inch). The refractory metal alloys of molybdenum and columbium were made in shorter lengths and generally did not have as good a surface finish or tolerance. Dies coated with .010 inches of zirconia and lubricated with graphite proved much superior to conventional tool steel dies resisting wear at extrusion temperatures up to 3200F. The die entry angle of 90 degrees was important in reducing the initial peak stresses to a controllable level and tooling failures were reduced by using high strength (Rc 55-60) steels which withstood pressures of 300,000 psi. The tendency for inertial separation (the phenomenon wherein the extrusion pulls itself apart because of the high inertial forces present) can be lessened and eliminated in many cases by the selection of low reduction ratios (15:1 or below) and low impact speeds. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1964
- Accession Number
- AD0608945
Entities
People
- J. M. Rippel
Organizations
- Westinghouse Electric Corporation