The range of precious metal sheet that Johnson Matthey make is wide. Our experience in a vast array of materials over the years enables our team of metallurgists to recommend on the suitability of a precious metal alloy for your application. Sheet is available in thin foils, blanked discs & washers, slit tape down to 1.0 mm wide, flattened wire, Turk’s head strip and thick discs & rectangles for sputtering targets in addition to the standard form. Precious metal sheet is rolled down from ingots that are cast, forged and individually batch identified using a variety of melting techniques. These include air melting, melting under a specified gas, vacuum melting and electron beam melting. Vacuum cast steel rolls are employed that are regularly re-ground to ensure flatness and a consistent surface finish. Johnson Matthey has clean room facilities for fine foils to minimise the risk of inclusions. A computer controlled high precision press is used to make discs, washers and complex shapes e.g.parts for bushings used for the production of glass fibre. Our analytical laboratories provide the full array of analysis techniques including Spectrographic and X-ray analysis, wet chemistry techniques and Scanning Electron Microscopy for surface examination to ensure material quality.
Some common uses of precious metal sheet are:
- platinum/rhodium alloy sheet in the glass industry for furnace linings and complex fabrications
- gold vacuum sealing rings and bursting discs
- various contacts and electrodes
- rhodium foils for X-ray filters
- iridium discs for radioactive sources
- iridium sheet for crucible manufacture
- platinum jewellery
RANGE OF MATERIALS IN THE PURE FORM:
Platinum, Palladium, Iridium, Rhodium and Gold – see purities below.
AS PLATINUM ALLOYS:
-Platinum Rhodium (5%, 6%, 8%, 10%, 13%, 20%, 25%, 30% or 40%)*
-Platinum Iridium (5%, 10%, 15%, 20%, 25% or 30%)*
-Platinum Zirconia (ZGS Platinum)
-Platinum 10% Rhodium/Zirconia
(ZGS 10% Rhodium Platinum)
(ZGS = Zirconia Grain Stabilised)
AS PALLADIUM ALLOYS:
-Palladium Silver (various alloys available) AS GOLD ALLOYS:-
-Gold Copper/Silver (JM625 alloy)
* Purity generally to 1000ppm.
THICKNESS & WIDTHS AVAILABLE
For platinum, ZGS platinum, 10% rhodium/ platinum and ZGS 10% rhodium/platinum:
down to 0.400 mm thick, maximum 500 mm wide. 0.400 mm – 0.025 mm thick, maximum 100 mm wide
For other platinum alloys, palladium and gold and their alloys:
down to 0.150 mm thick, maximum 200 mm wide. 0.150 mm – 0.025 mm thick, maximum 100 mm wide
For rhodium and iridium:
down to 0.500 mm thick, maximum 200 mm wide. 0.500 mm – 0.150 mm thick, maximum 100 mm wide 0.150 mm – 0.020 mm thick, maximum 50 mm wide (rhodium only)
Sizes outside those outlined above may be available in certain alloys
A range of hallmarkable platinum and palladium jewellery alloys are also available.
PHYSICAL PROPERTIES OF PRECIOUS METALS AND PURITY AVAILABLE