The high melting point, excellent chemical, mechanical and thermoelectric potential stability and high catalytic activity determine the industrial application of platinum and rhodium alloys to be more extensive and important than any other precious metal alloys.
Mainly used for:
(1) thermocouple manufacturing. PtRh10 / Pt thermocouple is the most accurate temperature measurement above 300℃ thermocouple, is also 630.74 ~ 1064.43℃ temperature within the international temperature benchmark, the general temperature measurement up to 1350℃(short time up to 1600℃); PtRh30 / PtRh6, PtRh13 / Pt, PtRh20 / PtRh5, PtRh40 / PtRh20 and other thermocouples can measure higher temperature.
(2) in the glass industry for the production of crucible, leakage plate, stirrers and electrodes and other heat and corrosion resistant devices.
(3) as a catalyst in ammonia oxidation and many other reactions.
(4) as a high temperature heating element, in which the furnace with PtRh40 alloy as heating element can work to 1800℃ in oxidizing atmosphere.
(5) used as electrical contacts, spark plug electrodes and potentiometer winding materials in the instrument industry.
Typical platinum-rhodium alloys include PtRh3.5, Ptrh7, PtRh10, PtRh25 and PtRh40, of which PtRh10 is known as the "standard alloy" and is the most widely used.
Rhodium wire resistance coefficient of 4.67 x 10-2 Ω was/m, the tensile strength of 726 MPa, the elongation is 46%. High frequency furnace argon protection melting, remelting 2 ~ 3 times, bottom injection, hot processing - cold processing into 0.02mm filament. It is a good high temperature thermocouple material. Rh-PtRh20 thermocouple has good high temperature stability and does not need strict cold end compensation. The operating temperature is 1800℃. Rh-PtRh8 and Rh-PtRh8 are also present.
