Oxide Deformation and Fiber Reinforcement in a Tungsten - Metal-Oxide Composite
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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Refractory oxide particles of urania UO2 and zirconia ZrO2 were added to a tungsten matrix and elongated into fibers by hot extrusion. Extrusion temperatures ranged from 3200 degrees to 4000 degrees F 1760 degrees to 2200 degrees C. The geometry of the oxide fibers appeared to be closest to that of an ellipsoid with the major axis alined in the extrusion direction. Oxide fibering was measured by an average length-to-width ratio of the fibers sectioned parallel to the major axis. the extent of oxide deformation was estimated in terms of strain components. Oxide-matrix deformation characteristics were related to the extrusion parameters by comparing the estimated oxide strain components to those of the composite. In terms of fibering, the greatest oxide elongation average length to width ratio 200, was obtained in tungsten-UO2 composites extruded at 3600 degrees F 1980 degrees C with a composite reduction of 18 to 1. values of average length to width ratio for tungsten-UO2 composites extruded at 3200 degrees and 4000 degrees F 1760 and 2200 degrees C were nearly equal average length to width ration 100 even though the composite reductions were 12 to 1 and 18 to 1, respectively. For a tungsten-ZrO2 composite extruded at 4000 degrees F 2200 degrees C, average length to width ratio 160. These length-to-width ratio values have no direct relation to the length-to-diameter ratio commonly used to describe fibered composites containing cylindrical fibers.
- Inorganic Chemistry
- Laminates and Composite Materials
- Metallurgy and Metallography