Irradiation growth rates of mechanically worked and alloyed uranium

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A method for mathematically formulating sets of p-values into a single index descriptive of the irradiation growth rate to be expected of the material to which they refer is applied to mechanically worked and to alloyed uranium. For uranium rolled within controlled temperature ranges, the growth index decreases with increasing temperature of rolling for a given reduction in area. Rolling at room temperature builds up a single (010) texture rapidly with increasing reduction. The compression texture is centred around the [114], [113] and [112] pole directions. The growth index in the rolling direction increases with increasing deformation. Beta heat-treatment of rolled uranium followed by water quenching substantially reduces the growth index. The texture of extruded uranium varies along the length of the rod. This variation can be correlated with micro-structure. At the front of the rod, there is a duplex (010)(110) texture associated with warm extrusion. In the middle the texture is (130) to (131) which is more representative of a recrystallization texture. At high reductions and temperatures of extrusion, a predominantly (100) texture is developed which leads to a negative growth index. A single β-quenching operation reduces the texture in extruded uranium, particularly the [100] component. Subsequent β-quenching appears to regenerate the texture. The effect of small additions of molybdenum, chromium and aluminium on the hot-rolled textures is to increase the (010) tension texture and reduce the (110) texture. For the same rolling conditions, the alloys have higher growth rates than unalloyed uranium.