Oxidation behaviour of electron beam physical vapour deposition β-NiAlHf coatings at 1100℃ in dry and humid atmospheres  

作　　者：Kai Yan Hong-Bo Guo Hui Peng Sheng-Kai Gong 

机构地区：[1]School of Materials Science and Engineering,Beihang University [2]Beijing Key Laboratory for Advanced Functional Material and Thin Film Technology,Beihang University

出　　处：《Rare Metals》2016年第7期513-519,共7页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundations of China(Nos.51071013 and 5120100);Natural Basic Research Program of China(Nos.2010CB631200 and 2012CB625100)

摘　　要：NiA1 intermetallic compounds attract increas- ing attention for high-temperature applications due to their combination of excellent properties, especially as metallic protective coatings on superalloys or as bond coats in thermal barrier coatings （TBCs）. Oxidation behaviour of the β-NiA1Hf coatings prepared by electron beam physical vapour deposition （EB-PVD） was investigated at 1100 ℃ for short time and 100h in 20% 02＋Ar and 15 % H20 ＋ Ar, respectively. The results of mass changes re- veal that the addition of minor reactive element Hf sig- nificantly improves the cyclic oxidation resistance of the 13- NiA1 coatings in both dry and humid atmospheres. During the initial oxidation stage, water vapour retards the phase transformation from 0-A1203 to a-A1203. Moreover, com- pared with the case in dry atmosphere, water vapour sig- nificantly reduces the surface roughness of the oxide scales formed on EB-PVD β-NiA1Hf coatings after 100 h cyclic oxidation, which corresponds with the difference of surface morphologies of the oxide scales.NiA1 intermetallic compounds attract increas- ing attention for high-temperature applications due to their combination of excellent properties, especially as metallic protective coatings on superalloys or as bond coats in thermal barrier coatings （TBCs）. Oxidation behaviour of the β-NiA1Hf coatings prepared by electron beam physical vapour deposition （EB-PVD） was investigated at 1100 ℃ for short time and 100h in 20% 02＋Ar and 15 % H20 ＋ Ar, respectively. The results of mass changes re- veal that the addition of minor reactive element Hf sig- nificantly improves the cyclic oxidation resistance of the 13- NiA1 coatings in both dry and humid atmospheres. During the initial oxidation stage, water vapour retards the phase transformation from 0-A1203 to a-A1203. Moreover, com- pared with the case in dry atmosphere, water vapour sig- nificantly reduces the surface roughness of the oxide scales formed on EB-PVD β-NiA1Hf coatings after 100 h cyclic oxidation, which corresponds with the difference of surface morphologies of the oxide scales.

关 键 词：β-NiA1Hf coatings Water vapour Oxidation Phase transformation ROUGHNESS 

分 类 号：TG174.4[金属学及工艺—金属表面处理]