This article contains comparison of key thermal and atomic properties of molybdenum and tungsten, two comparable chemical elements from the periodic table. It also contains basic descriptions and applications of both elements. Molybdenum vs Tungsten.
Molybdenum and Tungsten – About Elements
Source: www.luciteria.com
Molybdenum and Tungsten – Applications
Molybdenum
About 86% of molybdenum produced is used in metallurgy, with the rest used in chemical applications. The estimated global use is structural steel 35%, stainless steel 25%, chemicals 14%, tool & high-speed steels 9%, cast iron 6%, molybdenum elemental metal 6%, and superalloys 5%. Molybdenum (about 0.50-8.00%) when added to a tool steel makes it more resistant to high temperature. Molybdenum increases hardenability and strength, particularly at high temperatures due to the high melting point of molybdenum. Molybdenum is unique in the extent to which it increases the high-temperature tensile and creep strengths of steel. Molybdenum anodes replace tungsten in certain low voltage X-ray sources for specialized uses such as mammography. The radioactive isotope molybdenum-99 is used to generate technetium-99m, used for medical imaging. The isotope is handled and stored as the molybdate.
Tungsten
Tungsten is widely used metal. Approximately half of the tungsten is consumed for the production of hard materials – namely tungsten carbide – with the remaining major use being in alloys and steels. Mining and mineral processing demand wear-resistant machines and components, because the energies and masses of interacting bodies are significant. For this purposes, materials with the highest wear-resistance must be used. For example, tungsten carbide is used extensively in mining in top hammer rock drill bits, downhole hammers, roller-cutters, long wall plough chisels, long wall shearer picks, raiseboring reamers, and tunnel boring machines. The remaining 40% is generally used to make various alloys and specialty steels, electrodes, filaments, wires, as well as diverse components for electric, electronic, heating, lighting, and welding applications. High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten (as much as 18%), or combinations there of.
Molybdenum and Tungsten – Comparison in Table
| Element | Molybdenum | Tungsten |
| Density | 10.28 g/cm3 | 19.25 g/cm3 |
| Ultimate Tensile Strength | 324 MPa | 980 MPa |
| Yield Strength | N/A | 750 MPa |
| Young’s Modulus of Elasticity | 329 GPa | 411 GPa |
| Mohs Scale | 5.5 | 7.5 |
| Brinell Hardness | 1500 MPa | 3000 MPa |
| Vickers Hardness | 1530 MPa | 3500 MPa |
| Melting Point | 2623 °C | 3410 °C |
| Boiling Point | 4639 °C | 59300 °C |
| Thermal Conductivity | 138 W/mK | 170 W/mK |
| Thermal Expansion Coefficient | 4.8 µm/mK | 4.5 µm/mK |
| Specific Heat | 0.25 J/g K | 0.13 J/g K |
| Heat of Fusion | 32 kJ/mol | 35.4 kJ/mol |
| Heat of Vaporization | 598 kJ/mol | 824 kJ/mol |
