A Method for Performing Dynamic Tensile Extrusion of Materials at High Temperature

Report No. ARL-MR-0999
Authors: Joseph Koby, Jeffrey Ball
Date/Pages: May 2019; 31 pages
Abstract: Dynamic tensile extrusion is a well-established material characterization technique that involves firing a test projectile through a conical die. Our method adds the capability of performing extrusions after heating the projectile (and test barrel) with a 7-kW induction furnace. This new apparatus successfully extruded a 6.35-mm (0.25-inch) copper projectile to a diameter of 1.9 mm at a temperature of approximately 725 ℃. The extruded copper fragments were recovered, mostly undamaged, using a ballistic gel block. We performed three tests at a projectile velocity of approximately 450 m/s, with one test done at room temperature as a control. Up to twice the amount of a given projectile will extrude through the die at high temperature when compared with the amount extruded from a room-temperature test.
Distribution: Approved for public release
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Last Update / Reviewed: May 1, 2019