Mechanical properties at 2223Â K and oxidation behavior of Ir alloys

Compressive strengths of twelve Ir-1at%X binary alloys were evaluated at 2223 K to understand the strengthening effects of alloying elements. The alloying elements were selected from group 4 to group 10 in the periodic table. The maximum strength of about 65 MPa was obtained in Ir-Hf and Ir-Zr alloys. The effect of adding multiple alloying elements on strength was also investigated. Isothermal oxidation behavior was investigated at 1373 K for Ir alloys including Nb and/or Hf. The weight of all the tested alloys decreased linearly during the oxidation test, indicating that Ir oxide evaporated during oxidation.