Abstract
Ir-based superalloys are irreplaceable in some specific harsh conditions regardless of their cost and high density. In order to develop a new class of Ir-based superalloy for future ultrahigh-temperature applications, the microstructure evolution, phase relationships, and mechanical properties of Ir–Al–W–Ta alloys with γ/γ′ two-phase structure were investigated. Room- and high-temperature compressions at 1300 °C, and room-temperature nanoindentation for the Ta-containing Ir–6Al–13W alloys were conducted. The results show that the addition of Ta can significantly improve the high-temperature mechanical properties, but does not change the fracture mode of the Ir-based two-phase superalloys. The compressive strength of quaternary alloys can be attributed to the precipitation of γ′-Ir3(Al, W) phase and solid solution strengthening. The microstructure and mechanical properties of Ir–Al–W–Ta quaternary alloys exhibit promising characteristics for the development of high-temperature materials.
Funder
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals
National Key Research and Development Program of China Stem Cell and Translational Research
Subject
General Materials Science,Metals and Alloys