13.10/2023
POLEMA presented at the“BIOTECHMED” its innovative medical products
11.07/2023
POLEMA at INNOPROM in Ekaterinburg
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.
Tungsten sheets, plates, sputtering targets
Use
Tungsten sheets and plates are used in high and extremely high temperatures, as equipment for high-temperature furnaces (heat screens, supports and other reinforcing elements) and in the aerospace industry.
Thanks to its high absorbency of X- and gamma-rays, tungsten is widely used in the form of screens for weakening the flow of nuclear radiation in the nuclear power industry, collimators and radiotherapy.
Tungsten sputtering targets made in the form of plates are used to deposit thin barrier films during the metallization of semiconducting components of integrated circuits.
Sheets from W-PM tungsten
Chemical composition
Sheets are made from tungsten powder reduced with hydrogen from tungsten oxide. Tungsten oxide with a mass percentage of WO3 99.98 % (the typical value is 99.99% WO3 without including gas-forming elements) is used as raw material.
Grade | W, % | Element contents, ppm | |||||||||||
Na | Al | Si | P | K | Ca | Ti | V | Fe | Ni | Mo | ∑As, Cd, Sn, Sb, Pb, Bi | ||
PW1 | >99.98 | 6 | 7 | < 5 | 10 | 10 | 6 | 0.6 | 0.3 | 15 | 12 | 38 | < 9.5 |
∑ of impurities, not including C, N, O, H, F, P, S, Cl < 122 | |||||||||||||
PW2 | >99.98 | 0.5 | 1 | 6 | 6 | 50 | 10 | 0.1 | 2 | 10 | 5 | 55 | < 3 |
∑ of impurities, not including C, N, O, H, F, P, S, Cl < 160 |
Dimensions and surface condition
W-PM sheets and plates are made with a thickness of between 0.5 and 45 mm, with trimmed edges, or tooled in accordance with the client's needs.
The roughness of tooled surfaces is set at Ra <10 microns.
Thickness, mm | Width, mm | Length, mm |
From 0.5 to 0.7 | From 20 to 250 | From 50 to 1000 |
> 0.7 to 5.0 | From 30 to 310 | From 50 to 1000 |
> 5.0 to 7.0 | From 30 to 320 | From 50 to 700 |
> 7.0 to 15.0 | From 30 to 305 | From 50 to 350 |
> 15.0 to 20.0 | From 30 to 250 | From100 to 300 |
> 20 to 45 | Up to 150* | Up to 250* |
*Width and length are set depending on the plate's thickness.
Sheets and plates may be made with other maximum dimensions for width, length and thickness - for example, with a thickness starting at 0.3 mm - based on the client's request.
Nonflatness
The nonflatness of thin sheets with a thickness of up to 3 mm is as follows: < 2 mm per 100 mm of length; and, for sheets with a thickness of more than 3 mm with no tooling: < 1 mm per 100 mm of length.
At the client's request, sheets are produced with more rigorous nonflatness requirements.
Lack of internal defects, microstrucure, density
At the client's request, sheets and plates are delivered with control for micro- and macro-structure, mechanical properties and density.
Sample microstructures of tungsten sheets with controlled parameters
*Fig.1: W-PM sheet, thickness 1 mm, x100, density of material 19.21 g/cm3, hardness HRC 46.
*Fig.2: W-PM sheet, thickness 5 mm, x100, density of material 19.25 g/cm3, hardness HRC 44
*Fig.3: W-PM plate, thickness 8 mm, x100, density of material 19.25 g/cm3, hardness HRC 43
Rolling of precision sheet W99.95-PM
Requirements for the chemical composition and dimensions of W99.95-PM rolled stock are set that meet the ASTM B760 standard, along with heightened surface quality requirements with respect to State Standard 23922 for W-PM sheet.
Dimensions, surface condition
Thickness, mm | Thickness tolerances, % maximum | Width, mm | Length, mm |
From 0.5 to 1.0 | ± 10 | From 10 to 200 | From 50 to 1000 |
> 1.0 to 15.0 | ± 10 | From 10 to 310 | From 50 to 1000 |
> 15.0 to 40.0 | ± 10 | From 10 to 310 | From 50 to 600 |
Maximum deviations for rolled stock width.
Thin sheet from 0.5 mm to 4.75 mm is made with trimmed edges (ends), with a width tolerances of ± 1.6, or with tooled ends with a width tolerances of ± 0.8 mm, unless otherwise requested by the client.
Maximum rolled stock length deviations do not exceed ± 1.6 mm per 304.8 mm of length, and camber is no more than 1.6 mm per 304.8 mm of length, unless otherwise requested by the client.
Thickness, mm | Flatness deviation, %, maximum |
From 0.5 to 4.75 | 4 |
> 4.75 to 15.9 | 5 |
Surface roughness of tooled rolled stock.
The parameter for roughness of a milled surface is no more than Rz 40; the parameter for roughness of a ground surface is no more than Ra 1.6.
Thermal treatment
Following pressure treatment, rolled stock is annealed for internal stress removal, unless the client has other needs regarding the condition of the material.
Chemical composition of W99.95-PM rolled stock
W99.95-PM is made from the same reduced tungsten powder as W-PM grade rolled stock (see above).
Grade | W, % minimum* | Impurities content, ppm, maximum | ||||||
Fe | Al | Ni | Si | C | O | N | ||
W99.95-PM | 99.95 | 80 | 50 | 50 | 50 | 50 | 100 | 100 |
* the mass percentage of tungsten is determined by subtracting from 100% the total of controlled metallic admixtures, without including the gas-forming elements C, O, N, S, H, F, Cl.
Grade | W, % | Impurities content, ppm * | |||||||||||||
C | O | N | Fe | Al | Ni | Si | Ca | Na | K | Mo | P | S | As | ||
W99.95-PM | 99.986 | 15 | 40 | 20 | 13 | 2 | 15 | 6 | 6 | 6 | 20 | 45 | <1 | 10 | 1 |
* the total content of metallic impurities, determined using mass-spectrometry with inductively couple plasma (ICP-MS), does not exceed 0.0138 % (138 ppm).
Tungsten sputtering targets W99.95-PM
Tungsten sputtering targets are made in the form of tooled drawings and discs with dimensions and surface conditions set according to the plans agreed upon with the client.
Grade | W,%, minimum* | Impurities content, ppm, maximum | ||||||
Fe | Al | Ni | Si | C | O | N | ||
W99.95-PM | 99.95 | 80 | 50 | 50 | 50 | 100 | 100 | 100 |
∑ of metallic impurities < 500 ** |
* the mass percentage of tungsten is determined by subtracting from 100% the total of controlled metallic impurities without including the gas-forming elements C, O, N, S, H, F, Cl.
** metallic impurities are determined using mass-spectrometry with inductively coupled plasma (ICP-MS).
Advantages:
- the chemical purity of products from metallic admixtures and harmful interstitial impurities, ensures better mechanical characteristics of the material and operating properties of the products when working at high temperatures or with radioactive loads;
- it is possible to deliver rolled stock and products ranging from thin sheets to large-size plates tooled according to the client's plans;
- homogenous microstructure;
- varied product design to satisfy the client's individual needs.