Microstructure, oxidation resistance and high-temperature strength of a new class of 3D open-cell nickel-based foams

摘要

The 3D reticulated Ni-Cr-Fe alloy foams with 34-36 wt.% Cr and 20-24 wt.% Fe were synthesized by co-deposition of chromium and iron onto open-cell nickel foams, and then were homogenized to remove concentration gradients. Emphasis was placed on the research on the oxidation resistance behavior of newly developed Ni-Cr-Fe alloy foams with changing alloy composition, and the results were compared with those of Ni-25Cr and bare nickel foams at 800-1000°C. The room and high-temperature compression behavior of Ni-Cr-Fe alloy foams was also examined, respectively. The results show that the Ni-36Cr-24Fe alloy foam exhibits the best oxidation resistance among the Ni-34Cr-20Fe, Ni-35Cr-22Fe, Ni-25Cr and bare nickel foams after oxidation at 1000°C for 120 h. As the Cr and Fe contents increase, the yield stress and the plateau stress of the Ni-Cr-Fe alloy foams increase during the room and high -temperature compression tests. Whereas the compressive strength of the Ni-Cr-Fe alloy foams decreases with the increasing temperature at the same strain rate.