Authors: Q Pang Z L Hu G H Wu
Publish Date: 2016/10/10
Volume: 25, Issue: 12, Pages: 5189-5200
Abstract
Metallic foams with a high fraction of porosity low density and highenergy absorption capacity are a rapidly emerging class of novel ultralight weight materials for various engineering applications In this study YCr and CeCrcoated NiCrFe alloy foams were prepared via the pack cementation method and the effects of Y and Ce addition on the coating microstructure and oxidation performance were analyzed in order to improve the oxidation resistance of opencell nickelbased alloy foams The results show that the CeCr coating is relatively more uniform and has a denser distribution on the surface of the nickelbased alloy foam The surface grains of the CeCrcoated alloy foam are finer compared to those of the YCrcoated alloy foam An obvious Ce peak appears on the interface between the coating and the alloy foam strut which gives rise to a “siteblocking” effect for the shortcircuit transport of the cation in the substrate Xray diffraction analysis shows that the YCrcoated alloy foam mainly consists of Cr Fe Ni and Ni Cr phases in the surface layer The CeCrcoated alloy foam is mainly composed of Cr and Ni Cr phases Furthermore the addition of Y and Ce clearly lead to an improvement in the oxidation resistance of the coated alloy foams in the temperature range of 9001000 °C The addition of Ce is especially effective in enhancing the diffusion of chromium to the oxidation front thus accelerating the formation of a Cr2O3 layerThis study is financially supported by National Natural Science Foundation of China Grant No 51501133 and the Universities of Hubei Province outstanding young scientific and technological innovation team plans Project NoT201629 The authors would like to take this opportunity to express their sincere appreciation
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