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Design and Stress Analysis of Extraterrestrial ... - The Black Vault

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"APPENDIX<br />

STRENGTH CHARACTERISTICS OF MATERIALS<br />

USED IN EXTRATERRESTRIAL ENGINES'<br />

Uranium<br />

Uranium is a light s<strong>of</strong>t metal with high density (P 18.9 g/cm3);<br />

it is easily oxidized in air; however, a brown oxide film <strong>of</strong> uraniumi<br />

shields metal from further corrosion at room temperature. It melts<br />

at 11330C. <strong>The</strong> cbefficient <strong>of</strong> linear expansion a = 15.2710-6 ;<br />

16.2"10- 6 ; 20.5l10-6 I/0C at temperatures25-125; 125-325; 325-650 0 C<br />

respectively. <strong>The</strong> heat conductivity <strong>of</strong> uranium can be calculated<br />

using the formula X : 241.11 + 0.?3t W/m° 0 . <strong>The</strong> average indices <strong>of</strong><br />

elastic properties at room temperature are: the modulus o elosti -1 ty<br />

E = 2.0.106 daN/cm2, the Polsson coefficient p = 0.2, yield strength<br />

a0.2 = 20 daN/mm 2, ultimate stress a, = 60 daN/mm2. Short-term<br />

strength <strong>of</strong> uranium at high temperatures is given in Table A-.!.<br />

<strong>The</strong> spread in the strength values is<br />

processing techniques used.<br />

caused by the various uranium<br />

<strong>The</strong> variation in the modult.s <strong>of</strong> elasticity tild the Poispon<br />

coefficient as a function <strong>of</strong> temperature is shown in Fig. A.lI<br />

IV. S. Chirkin. <strong>The</strong>rmophysical properties <strong>of</strong> materials in nuclear<br />

technology. H<strong>and</strong>book, Atondizdat, 1968. High-melting mraterials ir<br />

machine building. H<strong>and</strong>book, M., "Mashinostroyen-ye," 1967. ichmelting<br />

metal materials for space technology, coll., ied-vw " 1 .1r,"<br />

1966.<br />

635

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