23.12/2022
Merry Christmas and Happy New Year 2023!
27.06/2022
POLEMA’s QMS confirmed its compliance with ISO 9001:20015
POLEMA JSC confirmed the compliance of the current QMS with the requirements of ISO 9001:2015.
03.06/2011
Progressive materials for multi-functional vacuum coatings
Application fields of materials for multi-functional vacuum coatings, characteristics of sputtering targets and evaporable sources used for technologies of physical deposition of hardening, protective, decorative and light-reflecting coatings, resistive, switching and transparent electro conductive films.
24.05/2011
Molybdenum and tungsten products for production of leucosapphires
POLEMA JSC is the leading global manufacturer of chromium, molybdenum, tungsten products, metal powders and composite materials.
Molybdenum electrodes
The glass industry is a major consumer of metallic molybdenum. Experience has shown molybdenum to be a superior material for electric heating during smelting of glass and basalt. This industry's use of molybdenum in the form of electrodes is conditioned by the following characteristics of the material:
- high elasticity modulus, resistance to plastic deformation and sufficient tensile strenght at the melting temperatures of glass and basalt;
- good heat conductivity;
- a low coefficient of heat expansion;
- resistance to corrosion in molten solutions;
- no influence on the color or transparency of glass;
- good machinability.
Mo99.95-PM electrodes are used in electric furnaces to smelt container and flat glass, technical glass, and basalt. Smelting glass and basalt in electric furnaces makes it possible to conduct the boiling process with greater productivity.
The chemical purity of electrode material (99.95% Mo) and the special program of temperature-deformation processing of stock used at JSC POLEMA allows to get products with high density and resistance to creeping (deformation) at the working temperatures for glass boiling.
Characteristics
Electrodes are delivered in annealed condition in the form of tooled rods or plates based on drawings agreed upon with the client.
Based on the order, electrodes can be produced with connective threads.
Electrode density is > 99%, and Vickers hardness HV 10 ranges from 160 to 210.
To increase resistance to creeping (bending, deformation), the average grain size of the microstructure of electrodes upon delivery is set within the range from 50 to 300 microns.
| Electrode type |
Diameter, mm |
Tolerances, mm |
Roughness Ra |
Length tolerances, mm |
| Turned | From 25 to 30 | ± 0.26 | 2.5 | <± 6.35 |
| > 35 to 50 | ± 0.31 | 2.5 | ||
| > 50 to 80 | ± 0.37 | 2.5 | ||
| Grinded | From 25 and more | ± 0.08 | 1.25 |
Electrode lengths and diameters of more than 80 mm are set based on client`s request.
| Grade | Mo,% | Impurities, ppm, maximum | |||||||||||
| O | N | C | Fe | Al | Ni | Si | Mg | Na | K | Ca | W | ||
| M99.95-PM | >99.95 | 70 | 50 | 100 | 100 | 30 | 50 | 50 | 20 | 30 | 80 | 40 | 130 |
| ∑Fe, Si, Ni, Al, W, Mg, Na, K, Ca <400 | |||||||||||||
| Total content of metallic impurities <500 | |||||||||||||
|
Electrode dimensions |
Mo, % | Impurities, ppm | |||||||||||
| O | N | C | Fe | Al | Ni | Si | Mg | Na | K | Ca | W | ||
| Ø48x1000 | >99.95 | 60 | 20 | 27 | 44 | 10 | 10 | 10 | 10 | 10 | 30 | 10 | 130 |
| Ø50.8x631 | 40 | 20 | 50 | 43 | 10 | 10 | 10 | 10 | 10 | 20 | 10 | 115 | |
| Ø63x1000 | 70 | 20 | 14 | 37 | 10 | 10 | 10 | 10 | 10 | 30 | 10 | 130 | |
The structure of a Mo99.95-PM large-grain electrode, which ensures high resistance to creeping
Advantages:
- high purity of the material;
- minimal content of interstitial impurities;
- maximal density;
- homogenous structure throughout the entire length;
- high tensile strength and operating endurance;
- lack of effect on the color and transparency of glass;
- good machinability.
