High-Temperature Oxidation Behavior of Pt-10Rh-Zr(Y) Alloys and its Influence on their Mechanical Properties

In most cases, platinum-based alloys are mainly used in high-temperature oxidation environments, and mastering their oxidation behavior and the impact of oxidation on performance is crucial. Two new platinum-based high-temperature alloys, Pt-10Rh-0.5Zr and Pt-10Rh-0.5Zr-0.2Y, were designed and prepared in this study. The research focuses on the high-temperature oxidation behavior of the alloys in air and the influence of oxidation on the room temperature mechanical properties of the alloys. The results show that the relationship between oxidation weight loss and temperature of these two platinum-based alloys conforms to the Arrhenius equation within the temperature range of 1400–1600 ℃, and the oxidation resistance of Pt-10Rh-0.5Zr-0.2Y alloy is better than that of Pt-10Rh.0.5Zr alloy. Examination of the surface and fracture morphology of these oxidized platinum-based alloys revealed that zirconium and yttrium oxide particles, such as ZrO2 and Y2O3, with different morphologies and structures were formed. The study also found that adding a small amount of zirconium and yttrium can significantly improve the room temperature ultimate tensile strength of Pt-10Rh alloy. However, after 20 h of high-temperature oxidation treatment at 1400 and 1500 °C, the tensile strength and plasticity at room temperature of both alloys showed a significant downward trend. Especially, the room temperature plasticity of Pt-10Rh-0.5Zr-0.2Y alloy decreased by more than 80% and exhibited a brittle fracture mode. Our research will contribute to the design and development of new high-temperature platinum-based alloys.