Processing of Iridium and fabrication of finished products

A production subsidiary of Group of Companies Precious Metals Of Urals JSC Urals?Ї Innovative Technologies has engineered a technological structure for processing of various types of iridium either raw or utilized iridium materials. In the result of application of original process of pyrometallurgical and hydrometallurgical refining it has become possible to produce Iridium ingots in short terms — from 10 days for scrap and up to 45 days for mineral raw materials. Depending on the mark of the bar the Iridium content makes 99,98% or 99,95%.

After electron-beam melting those bars or mono-crystals are becoming incoming billets for various Iridium products manufactured by means of metal treatment and welding.
A plastic deformation and further electric arc welding allow to get the full range of Ir products: ingots, plates, rolling, foil, rod, wire, disks, heated screens, crucibles, tips.

Pic. #1
Tools for growing of oxide single crystals in the form of plate by Stepanov’s method.

Pic. #2
Iridium seed holders for oxide crystals growing by Chohralski’smethod.

Application of Iridium and finished products

1. Containers and devices for growing of oxide monocrystals

Iridium is considered to by the perfect container material for manufacturing of oxide single crystals of garnets, sapphires (Al2O3), La-Ga silicates (La3Ga3SiO14), langotats, where temperature of growing varies from 1500°C up to 2100°C. The process takes pace in neutral or slightly oxidizing atmosphere during several days, and in time of crystallization of oxide melt the crucible undergoes significant mechanical stresses. Chohralski’s, Bridgeman’s, Stepanov’s processes are employed as methods in oxide crystals manufacturing, at the same time Iridium tools of various dimensions are applicable.
Except for crucibles it is necessary to produce heat screens of various configuration, seed holders, dies, etc.

The crucibles can be designed upon Customers’ request and they vary in dimensions:

• D is from 40 to 240 mm
• Height is from 20 to 240 mm

2. Spark plugs

Another industrial area where unique properties of iridium have been widely applied is production of spark plug tips for internal combustion engines. Iridium or alloys thereof (IrRh, IrReRu, IrRuRh) are employed as electrodes.

Aur company has accomplished the production of iridium based electrodes in the form of ø 0.5—1 mm spheres and ø 0.7—1х0.5—1 mm cylinders.

3. Disks for flaw detection and medical diagnostics

Ir192 isotope with half-life period of 74 days in the form of disks in diameter from 0.5 up to 4 mm and thickness from 0.12 up to 1 mm is used in flaw detection and medicine.

Strict requirements conduct iridium disks supplied to reactor for radiation:

• disk concavity should not exceed 10 microns (for disk thickness from 0.125 up to 0.3 mm);
• the surface roughness of disks should not exceed 0.25 microns;
• the disk edges should not be broken off during radiation, assembly and operation.

To eliminate the iridium disks concavity the special tool had been developed and produced. At the cutting process it allows to eliminate strong bending and stretching of iridium fibers.
It has been established that the grain size strongly affect the quality of disks. The finer grain, the more technological metal is, and the less edge chipping and the disk concavity are.
The designed technology provides the demanded grain size at all production stages.

Besides the unique technology of iridium disks fabrication in aluminum shell has been developed. Those products miss the grain chipping along the disk edges as their end face is completely covered by aluminum.

Disk size varies in diameter from 2 to 6 mm, in thickness from 0,125 to 0,5 mm.
Diameter of wire cylinder ranges from1 to 3 mm, and the length thereof from 1 to 3 mm.

4. Semi-finished products

Mentioned above technologies of Iridium processing make it possible to develop and to produce high-quality semi-finished Products:

• bars of 700 to 7000 grams of net weight;
• wires of 0,06 to 0,6 mm in diameter;
• strips of 0,1 to 3 mm thickness either annealed or not;
• iridium foil with the thickness from 0,01 to 0,09 mm.

5. Chemical compounds

The composition based on Iridium alloys (as hexachloriridium acid, iridium chloride, etc) are widely used for fabrication of iridium-oxide anodes in water- freshening units, iridium coatings, production of iridium-nickel catalysts for chemical industry.

The team of professional engineers and customer oriented personnel will anticipate the needs of our Customers and will provide the full support and assistance in order to achieve the benefits of consumers!