Platinum-iridium alloys have high melting point, high density, high hardness, high strength, and high elasticity, and these properties increase with increasing iridium concentration. (1) The alloy containing more than 10% iridium has age hardening effect and increases with the increase of iridium concentration, but the precipitation rate is low. (2) The resistivity of Pt-Ir alloy increases with the increase of Ir concentration, while the resistance temperature coefficient decreases. Pt-Ir alloy has low contact resistance, but it is easy to be polluted by organic atmosphere, which increases the contact resistance. Platinum-iridium alloys exhibit positive thermoelectric potentials for platinum and increase with increasing iridium concentration. (3) The addition of iridium to platinum significantly improves the chemical corrosion resistance of platinum, and alloys containing more than 30% iridium are actually not corroded by boiling aqua regal. (4) With the increase of iridium concentration and heating temperature, the volatilization weight loss of platinum-iridium alloy increases. (5) Platinum-iridium alloy has high deformation resistance and work hardening rate, and the work performance decreases with the increase of iridium content. The intragrystal segregation and dendrite are well developed, and the alloy can only be cold processed after high temperature hot working.
(1) Platinum-iridium alloys have high melting point, high density, high hardness, high strength, and high elasticity. These properties increase with the increase of iridium concentration.
(2) The alloy containing more than 10% iridium has age hardening effect and increases with the increase of iridium concentration, but the precipitation rate is low.
(3) The resistivity of Pt-Ir alloy increases with the increase of Ir concentration, while the resistance temperature coefficient decreases. Pt - iridium alloy has low contact resistance, but it is easy to be polluted by organic atmosphere, which increases the contact resistance. Platinum-iridium alloys exhibit positive thermoelectric potentials for platinum and increase with increasing iridium concentration.
(4) The addition of iridium to platinum significantly improves the chemical corrosion resistance of platinum, and alloys containing more than 30% iridium are actually not corroded by boiling aqua regal.
(5) With the increase of iridium concentration and heating temperature, the volatilization weight loss of platinum-iridium alloy increases.
(6) Platinum-iridium alloy has high deformation resistance and work hardening rate, and the work performance decreases with the increase of iridium content. The intragrystal segregation and dendrite are well developed, and the alloy can only be cold processed after high temperature hot working.
