QUESTIONS? GIVE US A CALL

Call us toll free: 1-800-394-9979 +1-800-394-9979
Call us toll free: 1-800-394-9979 +1-800-394-9979

Molybdenum

Recognized for excellent strength at high temperatures, its high melting point of 2610°C (4730°F), and its high resistance to corrosion

Properties
Molybdenum is a silvery white metal. It is softer and more ductile than tungsten, its sister element.

Atomic No. 42
Atomic Wt. 95.94
Specific gravity 10.34
Melting Point 2617°C
Coefficient of Thermal Expansion 4.8 X 10-6/°K
Specific Heat 0.060 cal/g/°K
Ultimate Tensile Strength (Room Temperature, Annealed) 95–115 ksi
Yield Tensile Strength (Room Temperature, Annealed) 80–95 ksi
Poisons Ratio 0.30
Modulus of Elasticity 4.63 X 107 psi
Recrystallization Temperature 900°C to 1300°

Molybdenum EDM, molybdenum cruicbles, molybdenum tubes or molybdenum tubing are all available from MTI Albany.
LABORATORY APPLICATIONS
In air or oxygen-containing atmospheres, molybdenum is not oxidized to any considerable degree at temperatures below 400°C (750°F). At 400°C (750°F) and up molybdic oxide is formed and begins to sublime.

It is recommended that for high temperature applications, except for brief periods, fusions should be performed in a vacuum or inert atmosphere. The crucibles could then be heated up to about 2100°C (3800°F).
General Corrosion Resistance
Molybdenum has the ability to withstand many non-oxidizing mineral and organic acids. It will corrode in alkalis in the presence of oxidizing materials. The metal is not affected by many molten metals and glasses. It is resistant to molten lead, gallium, lithium, sodium, potassium and bismuth. Molybdenum begins to oxidize in air at a temperature of 400°C.

This data is based on laboratory testing only. Your in-plant results may differ. Testing is recommended under other conditions as needed.
Molybdenum has the ability to withstand many acids including sulfuric, hydrochloric, hydrofluoric, and most organic acids, as well as many molten materials, such as metals, alloys glasses, compounds, etc. Molybdenum is corroded by alkalis in the presence of oxidants.

Molybdenums high melting point makes excellent for use as vapor deposition boats and dishes. Vessels of molybdenum have also been used for such applications as processing nuclear fuel pellets at temperatures up to 1650°C (3000°F). In addition, molybdenum crucibles are durable and will withstand repeated rough handling.

Corrosion Resistance of Molybdenum


SUBSTANCE
  REACTION

Air or Oxygen
  Beginning oxidation at 400°C (750°F) Strong oxidation above 600°C (1110°F) Sublimation of MoO2 above 700°C (1300°F)
Ammonia
  Slight, but complete corrosion
Aqueous Ammonia
  No Reaction
Aqua Regia
  Cold, dilute or concentrated; no reaction
Argon
  No reaction

Boron
  Boride formation at high temperatures
Bromine
  No reaction up to 450°C (840°F) Reaction at red heat
Carbon or Hydrocarbon
  Carbide formation above 1100°C (2010°F)
Carbon Dioxide
  Oxidation above 1200°C (2200°F)
Carbon Monoxide
  Carbide formation above 1400°C (2550°F)

Aqueous Caustic Soda
  No reaction
Molten Caustic
  Slight reaction with access to air Rapid dissolution in presence of oxidants (e.g. KNO3, KNO2, KCIO3, PbO2)
Chlorine
  Reaction above 300°C (750°F)
Fluorine
  Room temperature; vigorous attack
Helium
  No reaction

Hydrochloric Acid
  Dilute and warm; rapid corrosion Concentration: slow reaction
Hydrochloric-Sulphuric Acid
  Cold, dilute or concentrated; very slight reaction
Hydrofluoric Acid
  Warm or Cold: no reaction
Hydrofluoric Acid with Nitric Acid
  Warm or Cold; dissolves quickly
Hydrogen
  No reaction up to maximum temperature

Hydrogen Sulphide
  MoS2 forming at 1200°C (2200°F)
Iodine
  No reaction up to 500°C (812°F)
Nitric Acid
  Cold: slight reaction Warm: rapid attack
Nitric Oxide
  Oxidation to MoO3 at red heat
Nitrogen
  No reaction up to maximum temperature

Oxidizing Agents
  Molten KNO3, KNO2, Na2O2, K2CO3, PBO2 KClO3 give fierce reaction
Phosphorus
  No reaction up to maximum temperature
Potassium or Sodium Hydroxide
  Cold aqueous solution: no reaction Warm aqueous solution: slight reaction Molten: rapidly soluble

Silicon
  Silicide formation above 1100°C (2010°F)
Sulphur
  Sulphide formation above 440°C (820°F)
Sulphur Dioxide
  Oxidation to MoO3
Sulphuric Acid
  Dilute at 110°C (230°F): slow corrosion Concentrated at 200°C (390°F): rapid
Water
  No attack
Water vapor
  Rapid Oxidation at 700°C (1290°F)

Molten Metals:
  Molten: Strong attack
Aluminum, Iron, Cobalt, Nickel, Tin, Zinc
  Molten: slight attack
Lead, Cesium, Gallium, Potassium, Lithium, Sodium, Magnesium, Mercury, Bismuth
  Molten: highly resistant
Glass Melts
  Highly resistant
Refractory Oxides (e.g. Al2O3) BeO, MgO, ThO2, ZrO2
  No attack