Introduction

Molybdenum (Mo) is a metallic, silvery-white element. It is a chemical element of the 6th group of the periodic system with an atomic number of 42. The 31 isotopes are known from ⁸³Мо until ¹¹³Мо. The 6 of these isotopes are stable: ⁹²Мо, ⁹⁴Мо – ⁹⁸Мо. These 6 isotopes and ¹⁰⁰Мо (Т_½ = 1.00^•10¹⁹ year) are existing in nature in the form of molybdenum sulphide and lead molybdate. The unique physical properties of molybdenum and related alloys have found many applications in modern industry.

Physical Properties of Molybdenum

Special features of Molybdenum

Molybdenum is a transition metal. The pure Molybdenum is very hard, and has one of the highest melting points of all pure elements. Molybdenum is a refractory metallic element used principally as an alloying agent in steel, cast iron, and superalloys to enhance hardenability, strength, tough- ness, and wear and corrosion resistance. To achieve desired metallurgical properties, molybdenum, primarily in the form of molybdic oxide or ferromolybdenum, is frequently used in combination with or added to chromium, columbium (niobium), manganese, nickel, tungsten, or other alloy metals. With the especial intrinsic properties of molybdenum and its alloys, applications in modern industry have grown significantly. The contemporary industrial technology requires materials withstanding harsh corrosive environments at elevated temperatures with high stress resistance. Moreover, molybdenum finds significant usage as a refractory metal in numerous chemical applications, including catalysts, lubricants, and pigments. Few of molybdenum's uses have acceptable substitutions.

Advantages

Molybdenum can withstand very high temperatures.
Molybdenum has a high melting point.
Molybdenum can withstand many acids.
Thermal conductivity is approximately 50% higher than that of steel, iron or nickel alloys.
The electrical conductivity is the highest of all refractory metals.
Molybdenum has relatively high tensile strength.
The coefficient of thermal expansion of molybdenum is almost linear with temperature over a wide range.

Applications

Alloying agent for alloys to increase hot strength, toughness and corrosion resistance.
Electrical and electronic industries as material for production of the: cathodes, electrodes for electrically heated glass furnaces and forehearths, current leads for thorium cathodes, cathode supports for radar devices, magnetron end hats, core- and support wires for the lighting technology, boats and coils for resistive evaporation, mandrels for winding tungsten filaments.
In nuclear and missile industries as material for production of the high-temperature structural parts: nozzles, leading edges of control surfaces, support vanes, struts, reentry cones, heal-radiation shields, turbine wheels, heat sinks, pumps.
In chemical industry for production of the: catalysts , lubricants, smoke suppressants.
Acid service in chemical process industries.

Flokal can provide the molybdenum alloys:

TZM (Titanium-Zirconium-Molybdenum)

Molybdenum alloy TZM is an alloy of molybdenum, titanium, zirconium and carbon with unique properties especially useful for high strength and high temperature requirements.

Chemical Formula: Mo + 0.40-0.55% Ti + 0.06-.012% Zr + 0.01-0.04% C

It has a higher recrystallization temperature, higher creep strength and higher tensile strength than pure molybdenum. The combination of high hot hardness, high thermal conductivity, and low thermal expansion are allowing use TZM for production of the:

Rocket nozzles.
Tools for metalworking.
Die bodies for hot stamping.
Heat shields for furnaces, structural parts, and heating elements.
Base bodies for X-ray targets for medical diagnostics.

MHC (Molybdenum Hafnium Carbide)

The chemical composition of the molybdenum blended powder used for manufacturing the wrought bar shall conform to the following limits:

Mo(Balance)

Ni max. 0.005 %

Si max. 0.005 %

Fe max. 0.010 %

C 0.05 -0.15 %

Hafnium 0.8 -1.4 %

The MHC alloy bars can be supplied in the recrystallized condition upon request. All sizes of recrystallized bar shall exhibit hardness (mid-radius) of 215 DPH maximum. Tensile tests are conducted at room temperature (20°C – 30°C) with test specimens made and tested to Specification ASTM E-8 using a strain rate of 0.002 to 0.005 in/in/min through 0.6 % offset and 0.02 to 0.05 in/in/min to fracture. Tensile properties in the longitudinal direction, using such specimens taken from the center of round bars up to 1 ¼ inch diameter and from mid-radius location for larger bars. The MHC has higher recrystallization temperature, higher high-temperature strength, better creep resistance than pure molybdenum and higher high-temperature strength then TZM. It makes suited for die applications (particularly for brass extrusion).

ML (Molybdenum-Lanthanum)

Mo La is molybdenum doped of Lanthanum Oxide.  This composition has extraordinary resistance to recrystallization, ductility, and high-temperature deformation. Molybdenum lanthanum is an ideal material for applications requiring dimensional stability and strength at temperatures above than pure molybdenum or TZM alloy.

Type MoLa

Fe       0.010                   Ni 0.010                   Al   0.002

Si        0.010                   Ca  0.002                 Mg 0.002

C         0.010                   N  0.002                  O 0.14-0.2           

La₂O₃   0.2-0.6                Ti -  Zr -                  Mo - Bal.

Recrystallization Temperature >1500°C.

    Applications:

Wires for Lighting.

Sintered Crucibles and Substrate Holders for Molecular Beam Epitaxy.

Boats and Cups for the Annealing Filaments and Electrodes.

Semiconductor Base Plates.

Pins and Hats for Microwave Magnetrons.

Tube Components for Cathode Ray Tubes.

Components of Vacuum Furnaces.

Nozzles for Manufacturing Glass and Glass Fibers.

 MY (Molybdenum-Yttriumoxide)

MY is a molybdenum material which is doped with Yttrium Oxide and Cesium oxide. We supply MY as ribbon material. The distributions of the Y₂O₃ particles in molybdenum’s matrix are improving mechanical properties of the substance. With the result that the MY has a better adhesion to glass melts, higher recrystallization temperature, better weldability than pure Molybdenum. These unique properties of MY are using for conducting ribbon and sleeves for the lighting industry, boats and coils for resistive evaporation.

 MoW (Molybdenum-Tungsten)

The alloy of molybdenum with tungsten offers unique properties and it is developed for zinc industry. This alloy has good corrosion resistance for molten zinc. Furthermore, MOW is effective in rocket nozzles and has a good potential for application against erosive effects.

 MoRe (Molybdenum-Rhenium)

Supplement of molybdenum with rhenium allows increasing the ductility, weldability, recrystallization temperature, strength. It offers significant advantages for aplications in aerospace industry (rocket components), welded constructions (welding of high temperature delicate parts, e.g. thin foil), high temperature thermoelements.

  Different Molybdenum products