X-Ray Diffraction Determination of The Coefficients of Expansion of Alpha Uranium

Abstract

The unit cell dimensions of orthorhombic uranium have been determined over the temperature range —253° to 640°C. Above room temperature (27°C), these data were found to fit the equations at = a27 [1 + 17.2 × 10-6 (t —27) + 30.8 × 10-9 (t — 27)2] bt = b27[1 — 9.2 × 10-6 (t —27) + 40.4 × 10-⁹ (t —27) 2 — 67.5 × 10-12 (t —27)3] ct = c27[1+25.1 × 10-⁶ (t —27) — 21.3 × 10-9 (t —27)2 + 57.5 × 10-12 (t —27)3]. Mean coefficients were computed. Over the range —253° to 100°C, these were compared with dilatometer data.