Molybdenum Stock

Atomic Number: 42
Atomic Weight: 95.94
Density: (20°C) 10.22 g/CC
Melting Point: 2896 K, 2610°C, 4753°Fm
Boiling Point: 4912 K, 5560°C, 8382°F
Coefficient of Thermal Expansion: (20°C) 4.9 x 10-6/°C
Electrical Resistivity: (20°C) 5.7 microhms-cm
Electrical Conductivity: 30% IACS
Specific Heat: .061 cal/g/°C
Thermal Conductivity: .35 cal/cm2/cm°C/sec
Modulus of Elasticity: (20°C) 46 x 106 psi

Molybdenum provides corrosion resistance that is similar to tungsten. Molybdenum particularly resists non-oxidizing mineral acids. It is relatively inert to carbon dioxide, ammonia, and nitrogen to 1100°C and also in reducing atmospheres containing hydrogen sulfide. Molybdenum offers excellent resistance to corrosion by iodine vapor, bromine, and chlorine, up to clearly defined temperature limits. It also provides good resistance to several liquid metals including bismuth, lithium, potassium, and sodium.

Mass:
Density at 20° C gm/cc - 10.2
Density at 20° C lb/in 3 - 0.368

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Thermal Properties:
Melting Point, °C - 2610
Boiling Point, °C - 5560
Linear Coefficient of Expansion per °C - 4.9 x 10^-6
Thermal Conductivity at 20°C, cal/cm2/cm°C/sec. - 0.35
Specific Heat, cal/g/°C; 20°C - 0.061

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Electrical Properties:
Conductivity, % IACS - 30%
Resistivity, microhms-cm; 20°C - 5.7
Temperature Coefficient of Resistivity per °C (0-100°C) - 0.0046

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Mechanical Properties:
Tensile Strength at room temperature, psi - 100,000-200,000
Tensile Strength-500°C psi - 35,000-65,000
Tensile Strength-1000°C psi - 20,000-30,000

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Young's Modulus of Elasticity; lb/in²:
Room Temperature - 46 x 10⁶
500°C - 41 x 10⁶
1000°C - 39 x 10⁶

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Spectral Emissivity:
(Wave Length approx. 0.65) - 0.37 (1000°C)

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Working Temperature: 1600°C

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Recrystallizing Temp: 900-1200°C

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Stress Relieving Temp: 800°C

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Metallography:
Etchant - Hot H2O2; 6% sol
Polishing - Alumina - Rouge to finish

Heat Shields
Furnace Temperature, x F - 1832, 1832, 2012, 2012, 2400, 2400
Cold Shell Temperature, x F - 100, 100, 100, 100, 100, 100
Number of Shields (1 - 10) - 1, 2, 1, 2, 1, 2
Avg. Shield Emissivity Factor (0 - 1.0) - 0.60, 0.60, 0.60, 0.60, 0.60, 0.60
Cold Shell Emissivity Factor (.9 typ) - 0.90, 0.90, 0.90, 0.90, 0.90, 0.90

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Computed Shield Temperature IN x F
#1 Shield - 1484, 1646, 1637, 1811, 1965, 2167
#2 Shield - 1250, 1384, 1672

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Computed Heat Loss (KW/ft2) - 4.0, 2.4, 5.5, 3.3, 9.8, 5.9

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Furnace Temperature, x F - 2400, 2400, 2400, 2400, 2192, 2192
Cold Shell Temperature, x F - 150, 150, 150, 150, 100, 100
Number of Shields (1 - 10) - 3, 4, 5, 6, 1, 2
Avg. Shield Emissivity Factor (0 - 1.0) - 0.60, 0.60, 0.60, 0.60, 0.60, 0.60
Cold Shell Emissivity Factor (.9 typ) - 0.70, 0.70, 0.70, 0.70, 0.90, 0.90

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Computed Shield Temperature IN x F
#1 Shield - 2247, 2282, 2305, 2320, 1789, 1976
#2 Shield - 1976, 2087, 2151, 2194, 1517
#3 Shield - 1563, 1832, 1966, 2047
#4 Shield - 1444, 1723, 1869
#5 Shield - 1354, 1636
#6 Shield - 1282

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Computed Heat Loss (KW/ft2) - 4.0, 3.1, 2.6, 2.2, 7.3, 4.3