ATOMIC, STRUCTURAL, AND PHYSICAL PROPERTIES OF IRIDIUM
Iridium is the second densest of all elements. With a melting temperature of 2446°C (4435°F), it is exceeded only by the refractory group metals. It exhibits excellent high temperature properties and mechanical strength, being used in certain applications, unprotected, in air at temperatures exceeding 2000°C (3632°F). At these temperatures it also shows outstanding resistance to a variety of salts and oxides. It is unaffected by common mineral acids and aqua regia. This makes iridium an obvious choice for a whole range of high temperature applications. However, its high degree of stiffness and resistance to deformation render its fabrication into complex components difficult.
Johnson Matthey has spent many years developing an understanding of the methods of working iridium into component form. The installation of speciality melting equipment, hot rolling and drawing plant, and thermal deposition systems in our facilities at Royston near Cambridge in the UK, and at West Chester near Philadelphia in the USA, has resulted in a unique fabrication ability in iridium.
Products are available in the forms and dimensions overleaf.
IRIDIUM PRODUCTS AVAILABLE FROM JOHNSON MATTHEY PURITY
All Johnson Matthey iridium products are produced using starting material of 99.99% purity.
In addition, there are a number of specific impurity limits for contaminants which are known to have undesirable effects on product performance. A full list of these is available upon
request.
WIRE
Diameter from 4.0mm to 0.127mm ± 10% (0.157” to 0.005”). Available in continuous lengths or cropped to a minimum of 0.5mm ± 0.05mm (0.02” ± 0.002”).
SHEET
Up to 10kg (322 ozt) single ingot processing. Width up to 255mm (10.0”). Thickness from 5mm to 0.1mm (0.02” to 0.004”).
DISCS
All typical dimensions available. Specific applications dictate a high flatness tolerance. Within the range of sizes normally used in this area, specialised tooling enables discs to be produced to a flatness of ± 0.025mm (± 0.001”).
TUBES
All standard dimensions requested are available. Tubes are normally produced with a seam weld. Weld witness is not removed from internal bore.
CRUCIBLES
All standard sizes available (30cc to > 6000cc). Wall thickness 4.0mm to below 1.0mm (0.157” to 0.04”). Crucibles are supplied flat-bottomed, with an edge radius of = 6.0mm (0.236”).
OTHER
The above is a summary of typical products we are asked to produce. We welcome any enquiries for other iridium products.
N.B.
See also our data sheet on fIreformTM products – Iridium and Iridium Alloy Products and
Coatings.