Effect of Y distribution on the oxidation kinetics of NiCoCrAlY bond coat alloys

被引：62

作者：

Nijdam, T. J. ^{[1
,2
]}

Sloof, W. G. ^{[1
,2
]}

机构：

[1] Delft Univ Technol, Dept Mat Sci & Engn, NL-2628 CD Delft, Netherlands

[2] Netherlands Inst Met Res, NL-2628 CD Delft, Netherlands

来源：

OXIDATION OF METALS | 2008年 / 69卷 / 1-2期

关键词：

oxidation; diffusion; modeling; alumina; MCrAlY bond coating;

D O I：

10.1007/s11085-007-9080-z

中图分类号：

TF [冶金工业];

学科分类号：

0806 ;

摘要：

The relation between the Y distribution in the alloy and the growth kinetics of the developing oxide scale was studied for the thermal oxidation of two Ni-20Co-19Cr-24Al-0.2Y (at.%) alloys at 1,373 K: (i) a coarse-grain cast alloy with large Ni5Y intermetallic precipitates, and (ii) a fine-grain freestanding coating with small Ni5Y precipitates. Using a combination of experiments and model calculations, it is shown that the average growth kinetics of a NiCoCrAlY alloy are dependent on the size and distribution of Y-rich oxide inclusions (pegs) in the alpha-Al2O3 oxide layer. Alumina scales containing a high density of small Y-oxide inclusions grow faster than alpha-Al2O3 scales containing only a few, large Y-oxide inclusions. Upon oxidation of the freestanding coating, the Y-oxide inclusions in the scale attain their maximum size after the Y in the coating is completely consumed. After this point, a decrease in the average oxidation kinetics occurs.

引用

页码：1 / 12

页数：12

共 35 条

[1] SINGLE-CRYSTAL OF YAG - NEW FAST SCINTILLATOR IN SEM [J].