PtIr30 Soft‑Annealed (+A): Durable Contact Material for High‑AC Switches, Relays, and Aerospace Applications

The platinum-iridium material PtIr30 (in the literature also: Pt30Ir or Pt70Ir30) is used as contact material for switching contacts (switches and relays for higher alternating current loads with a long service life) as well as for laboratory devices or structural components such as satellite control nozzles that are mechanically stressed, thermally and corrosively heavily used. The mechanical, thermal and corrosive resistance increases with increasing iridium content. In an oxidizing atmosphere, increased weight loss occurs in platinum-iridium alloys. Further fields of application for this material are the use as potentiometer alloy as well as for clamping bands. The material is ductile, corrosion-resistant, oxidation-resistant up to 1000°C, abrasion-resistant, hardenable and resistant to high temperatures. It is non-cutting and machinable machinable, roll-clad and conditionally deductible from the gas phase.

Properties

General

Property	Temperature	Value
Density	20.0 °C	21.8 g/cm³

Mechanical

Property	Temperature	Value	Comment
Elastic modulus	20.0 °C	264 GPa
Elongation	20.0 °C	22 %
Hardness, Vickers	20.0 °C	250 - 270 [-]
Poisson's ratio	23.0 °C	0.39 [-]	Typical for Platinum
Shear modulus	20.0 °C	97 GPa
Tensile strength	20.0 °C	830 MPa
Yield strength Rp0.2	20.0 °C	570 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion	300.0 °C	8.6E-6 1/K
Melting point		1769 °C	Typical for Platinum
Specific heat capacity	23.0 °C	136 J/(kg·K)	Typical for Platinum
Thermal conductivity	23.0 °C	69 - 73 W/(m·K)	Typical for Platinum

Electrical

Property	Temperature	Value
Electrical resistivity	20.0 °C	3.4E-7 Ω·m

Chemical properties

Property	Value
Iridium	30 %
Platinum	70 %

AA Standards Grade 5004 – Aluminium 5000 Series Mechanical & Thermal Properties PtNi8.5 Alloy: Durable Contact Material for AC/DC Switching

Metal