Characteristics of tungsten and molybdenum

Release time:

2024-03-27

In life, molybdenum is located in the fifth period of Mendeleev's periodic table and in the VIB group. This is a transitional element. Molybdenum has an atomic number of 42 and an atomic weight of 95.94. Because the orbit of the valence layer is half-filled, molybdenum is a transition element. It exhibits a typical transition state between lithophile elements (8-electron ion configuration) and cuprophile elements (18-electron ion configuration). Popular Goldschmidt in the geochemical classification of elements called iron elements. (Tungsten and Molybdenum)

Then in nature, there are seven stable natural molybdenum isotopes. Table 1 lists their nuclear numbers and their proportions in natural mixtures. Table 1 Isotopic and distribution of molybdenum. According to the literature, an eighth natural isotope has been discovered. In addition, 11 man-made molybdenum radioisotopes were also found. Since the data are unknown, I will not repeat them here. Molybdenum is a silver white metal with an atomic radius of 0.14nm, an atomic weight of 235.5px / mol, and a coordination number of 8. The crystal is Az type body centered cubic system, space group is Oh( lm3m). Not yet found. Heterogeneous conversion. The lattice parameter of molybdenum at room temperature is between 0.31467 and 0.31475nm, which varies with the content of impurities.

Molybdenum has a high melting point and ranks sixth among natural elements. It is called refractory metal. See Table 2 (from Handbook of Physics and Chemistry, 60th Edition). Molybdenum has a density of 10.23 g/cm, which is about half that of tungsten (tungsten density is 19.36). g/cm). The thermal expansion coefficient of molybdenum is very low: 4.9 × 10 /℃ at 20~100 ℃; the thermal conductivity of molybdenum is high, 142.35w /(m · k); the resistivity of molybdenum is low: 5.17 ×-10 Ω · cm at 0 ℃; 24.6 ×-10 Ω · cm at 800 ℃; 72 ×-10 Ω · cm at 2400 ℃. Molybdenum is a paramagnetic substance and has a magnetic susceptibility of 0.93 × 10 cm/g at 25 ° C. with a purity of 99.99. The specific heat of molybdenum is 242.8J /(kg · k) at 25°C. Molybdenum has a relatively high hardness, with a Mohs hardness of 5 to 5.5. The heat of vaporization of molybdenum at the boiling point is 594kJ/mol. The heat of fusion is 27.6±2.9kJ/mol. 25 degrees Celsius under the heat of 659kJ/mol. Table 2 Refractory Melting and Boiling Points It is clear that molybdenum is extremely difficult to lose 7 or 8 electrons. This confirms that molybdenum is chemically relatively stable. Molybdenum is stable in air or water at room temperature or not too high.

Molybdenum wire standard and molybdenum wire grade

Development Status of Tungsten and Molybdenum Industry

2025-01-17

Plasma nitriding of molybdenum products

2025-01-13

The difference between pure five-axis machining and 3+2 axis machining.

2025-01-10

Tungsten-based high-density alloy W152

2025-01-08

Maitwei is not just tungsten and molybdenum.

2025-01-06

The composition, structure, types, and applications of sputtering targets.