Mechanisms of plastic deformation and fracture in coarse grained Fe–10Al–4Cr–4Y2O3 ODS nanocomposite at 20–1300°C

Abstract

The coarse-grained Fe–10Al–4Cr–4Y2O3ODS nanocomposite (denoted as FeAlOY) has been developed by the authors and shows promising potential for high-temperature structural applications at 1000–1300 °C. Compared to classical ODS alloys, the FeAlOY contains ten times higher volume fraction of the stable Y2O3 nanodispersion, which gives the alloy its high-temperature strength. Furthermore, the high content of Al in the matrix guarantees excellent oxidation resistance. In practice, one can expect that the FeAlOY is loaded in the temperature range of 20–1300 °C due to intermittent device operation. To ensure a safe operation, it is necessary to determine the tensile strength and ductility of the FeAlOY in the whole temperature range and detect the dominant mechanisms of strengthening, plastic deformation, and fracture in the characteristic temperature ranges. Above 1100 °C the FeAlOY reaches ultimate tensile strength of ∼ 100 MPa and plasticity of ∼ 1%. However, in the temperature range of 400–600 °C, the plasticity can climb above 40%. The achieved results can also be utilized for the design of the FeAlOY pieces shaping by hot pressing.

Keywords

• Fe–Al based ODS alloy
• Y2O3 nanooxides
• Grain microstructure
• Strength
• Ductility