Isothermal Oxidation Behavior of Dysprosium/S-Doped β-NiAl Alloys at 1200°C  

作　　者：Lu Wang Dongqing Li Jian Chang Hongbo Guo Shengkai Gong Huibin Xu 

机构地区：[1]School of Materials Science and Engineering, Beihang University [2]AVIC Shenyang Liming Aero-engine Group Corporation Ltd.

出　　处：《Journal of Materials Science & Technology》2014年第3期229-233,共5页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China (NSFC) under Grant Nos. 51071013 and 51231001;the National Basic Research Program (973 Program) of China under Grant Nos. 2010CB631200 and 2012CB625100

摘　　要：A β--NiAI alloy with normal purity, a S-doped and a Dy and S co-doped （Y-NiAI alloys were prepared by arc-melting and their corresponding S contents were less than 20 ×10-6, 33 ×10-6 and 22 × 10-6, respectively. The isothermal oxidation behavior of the alloys at 1200 ℃ was investigated and the extent of S segregation at the scale-alloy interface was determined by scanning Auger microscopy. S-doping had no significant effect on the phase transformation rate from e- to β-Al2O3, while the addition of Dy retarded this process. For the S- doped alloy, scale rumpling occurred only after 2 h thermal exposure and numerous large voids were observed at the scale-alloy interface where S segregated. In contrast to this, the oxide scale formed on the Dy and S co-doped alloy still remained flat even after 50 h isothermal oxidation and only small voids existed at the interface where S segregation was not detected.A β--NiAI alloy with normal purity, a S-doped and a Dy and S co-doped （Y-NiAI alloys were prepared by arc-melting and their corresponding S contents were less than 20 ×10-6, 33 ×10-6 and 22 × 10-6, respectively. The isothermal oxidation behavior of the alloys at 1200 ℃ was investigated and the extent of S segregation at the scale-alloy interface was determined by scanning Auger microscopy. S-doping had no significant effect on the phase transformation rate from e- to β-Al2O3, while the addition of Dy retarded this process. For the S- doped alloy, scale rumpling occurred only after 2 h thermal exposure and numerous large voids were observed at the scale-alloy interface where S segregated. In contrast to this, the oxide scale formed on the Dy and S co-doped alloy still remained flat even after 50 h isothermal oxidation and only small voids existed at the interface where S segregation was not detected.

关 键 词：NIAL Dy S Isothermal oxidation Phase transformation SEGREGATION 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG174.4[金属学及工艺—金属材料]