Isothermal Oxidation of Aluminized Coatings on High-Entropy Alloys

Entropy

Che-Wei Tsai¹  Kuen-Cheng Sung¹  Hideyuki Murakami²  Kzauki Kasai² 

[1] Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan;Surface and Interface Kinetics Group, National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan;

关键词: high entropy alloys;    aluminizing;    isothermal oxidation;   

DOI  :  10.3390/e18100376

来源: DOAJ

【 摘 要 】

The isothermal oxidation resistance of Al0.2Co1.5CrFeNi1.5Ti0.3 high-entropy alloy is analyzed and the microstructural evolution of the oxide layer is studied. The limited aluminum, about 3.6 at %, leads to the non-continuous alumina. The present alloy is insufficient for severe circumstances only due to chromium oxide that is 10 μm after 1173 K for 360 h. Thus, the aluminized high-entropy alloys (HEAs) are further prepared by the industrial packing cementation process at 1273 K and 1323 K. The aluminizing coating is 50 μm at 1273 K after 5 h. The coating growth is controlled by the diffusion of aluminum. The interdiffusion zone reveals two regions that are the Ti-, Co-, Ni-rich area and the Fe-, Cr-rich area. The oxidation resistance of aluminizing HEA improves outstandingly, and sustains at 1173 K and 1273 K for 441 h without any spallation. The alumina at the surface and the stable interface contribute to the performance of this Al0.2Co1.5CrFeNi1.5Ti0.3 alloy.

【 授权许可】

Unknown