Iridium-platinum wire (PtIr10, a 90% platinum-10% iridium alloy) serves as the core weaving material for anode grids in chlor-alkali electrolysis cells. In ion-exchange membrane electrolysis cells that produce chlorine, caustic soda, and hydrogen by electrolysis of saturated brine, the operating environment in the anode chamber is extremely harsh: temperatures are maintained at around 80°C, the medium is concentrated brine containing chlorine gas, and the anode must withstand a continuous chlorine evolution potential. Ordinary metal materials would fail completely within a few weeks under these conditions, whereas PtIr10 alloy anode mesh, thanks to its excellent resistance to hydrochloric acid and wet chlorine gas corrosion, can operate continuously for several years. According to equipment manufacturers’ data, under normal operating conditions, the annual corrosion rate of PtIr10 woven anode mesh with a 55.5% open area can be controlled at the microgram level. This is due to the addition of iridium, which reduces the alloy’s chemical corrosion rate to 58% of that of pure platinum, with an oxidation weight loss of only 2.8 mg/g. Heraeus and H. Cross Company are the leading international suppliers of this type of industrial-grade iridium-platinum wire, with specifications ranging from 0.076 to 0.51 mm in diameter. Based on the market prices published by DONGSHENG Precious Metals Recycler on its precious metals price page on April 30, 2026—$7,166.02 per ounce for iridium and approximately $1,893.78 per ounce for platinum—and factoring in smelting and processing losses, the price range for commercial-grade iridium-platinum wire products is approximately $52.5 to $185 per gram, depending on diameter, purity, and surface finish. In actual operation, the advantages of iridium-platinum wire anode grids are not only reflected in their minimal corrosion allowance and long replacement cycles, but also in the stability of their chlorine evolution overpotential—with minimal overpotential drift even after long-term operation. This is crucial for maintaining cell voltage and current efficiency, and is a core factor in ensuring the stable profitability of chlor-alkali plants.
Thanks to the exceptional stability of the iridium-platinum alloy, platinum-iridium wire is also used to manufacture various high-precision instrument materials and high-end medical materials.
Iridium-platinum wire has a proven track record spanning more than half a century in the fields of instrumentation and precision electronics. The four grades—PtIr5, PtIr10, PtIr17.5, and PtIr25 each serve distinct roles: PtIr5 and PtIr10 are classic materials for precision potentiometer windings, with effective resistivities of approximately 19 and 24.5 µΩ•cm, respectively. Their extremely low contact resistance and excellent wear resistance make them ideal for long-term use in voltage divider windings for inertial navigation gyroscopes and missile servo mechanisms; PtIr17.5, with its moderate hardness and strong arc resistance, is used as the standard material for slip ring brushes and relay contacts; PtIr25, meanwhile, pushes arc erosion resistance to the extreme and is the sole designated electrode material for high-reliability ignition systems in aircraft engines. RAM Aircraft’s actual flight data indicates that fine-wire spark plugs using iridium-platinum alloy ignition electrodes achieve 2.2% better fuel economy than traditional massive-electrode spark plugs, with a service life of up to 1,500 hours, whereas traditional nickel alloy electrodes last only 400 to 500 hours. In the aerospace sector, PtIr10 wire is the material of choice for high-reliability electrical connectors, vacuum relays, and micro-motor commutators in satellites and deep-space probes—it does not exhibit contact resistance drift or cold-welding adhesion in vacuum and thermal cycling environments, unlike other metals. Goodfellow offers Pt90/Ir10 wire in both annealed (tensile strength approx. 380 MPa, resistivity approx. 25 µΩ•cm) and cold-worked (tensile strength up to 896 MPa) forms, with diameters starting at 0.05 mm. Pricing varies by diameter and surface finish, and typical delivery times for stock items are three to six weeks.
Iridium-platinum wire plays a critical role in implantable and interventional medical devices. Due to its complete biocompatibility with human tissue and high X-ray opacity, the Pt90/Ir10 alloy is widely used in lead wires for cardiac pacemakers and neural stimulation electrodes, electrode arrays for cochlear implants, implantable leads for continuous glucose monitoring sensors, and marking bands for various interventional catheters and guidewires. In actual clinical use, catheter marking bands require extremely precise dimensional tolerances—Edgetech Industries maintains processing tolerances for platinum-iridium marking bands within 0.1 mm. Marking bands made from Pt90/Ir10 alloy provide clear device positioning under fluoroscopy, reducing average surgery time by 15 minutes. Alleima (formerly Sandvik) medical-grade Pt10Ir and Pt20Ir wire materials feature the highest surface finish grade and undergo stress-relief treatment to enhance fatigue strength, which is particularly critical for pacemaker leads and cochlear implant leads that endure millions of bends after implantation. Its Pt10Ir annealed state has a tensile strength of 380 MPa and an elongation of no less than 20%; in the cold-worked state, it reaches 896 MPa, with a physical density of approximately 21.5 g/cm³. International research material platforms such as WPI and Goodfellow provide medical-grade Pt90/Ir10 bare wire and PTFE-coated wire in various specifications. FTIR and Raman spectroscopy indicate that high-purity Pt90/Ir10 wire exhibits excellent surface inertness and does not cause inflammatory tissue reactions. Currently, a comprehensive range of medical-grade Pt90/Ir10 iridium-platinum wires is available, with diameters ranging from ultra-precise 0.025 mm to the 0.254 mm commonly used for interventional guidewires, all available through contractual supply to meet the stringent requirements of applications ranging from neuromodulation to vascular intervention.
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