Molybdenum metal & alloys

Molybdenum metal is usually produced by powder metallurgy techniques in which Mo powder is hydrostratically compacted and sintered at about 2100°C. Hot working is done in the 870-1260°C range. Moly forms a volatile oxide when heated in air above about 600°C and therefore high temperature applications are limited to non-oxidizing or vacuum environments.

Moly alloys have excellent strength and mechanical stability at high temperatures (up to 1900°C). Their high ductility and toughness provide a greater tolerance for imperfections and brittle fracture than ceramics.

The unique properties of molybdenum alloys are utilised in many applications:

  • High temperature heating elements, radiation shields, extrusions, forging dies, etc;
  • Rotating X-ray anodes used in clinical diagnostics;
  • Glass melting furnace electrodes and components that are resistant to molten glass;
  • Heat sinks with thermal expansivity matching silicon for semiconductor chip mounts;
  • Sputtered layers, only Ångstroms (10-7 mm) thick, for gates and interconnects on integrated circuit chips;
  • Sprayed coatings on automotive piston rings and machine components to reduce friction and improve wear.

For specialised applications, Mo is alloyed with many other metals:

  • Mo-tungsten alloys are noted for exceptional resistance to molten zinc;
  • Mo is clad with copper to provide low expansion and high conductivity electronic circuit boards;
  • Mo-25% rhenium alloys are used for rocket engine components and liquid metal heat exchangers which must be ductile at room temperature.

For more information see also:

Spherical agglomerates of Mo powder

Spherical Agglomerates of Mo powder
(lacy appearance), with solid spheres of the Ni-Cr alloy binder for the Mo powder

High temperature furnace

High temperature furnace with
molybdenum hot zone
(Courtesy of PLANSEE AG, Austria)

Applications of Molybdenum Metal and Its Alloys
Applications of Molybdenum Metal and its Alloys
This publication helps non-experts to learn how molybdenum metal is produced, what its physical, mechanical, and chemical properties are, and how those properties make molybdenum and its alloys the materials of choice in a wide range of applications.
IMOA Newsletter July 2007
Traditional and Emerging Applications of Molybdenum Metal and Its Alloys