Effect of Ag on the Hot Corrosion of NiAl Intermetallic Compound

The low ambient tensile ductility and inadequate high temperature strength and creep resistance have limited the applications of intermetallic compound NiAl as a structure material at high temperatures. A small addition of Ag could increase the strength of NiAl. In this study, hot corrosion behavior...

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Bibliographic Details
Main Authors: Liu S.N., Su W., Lv W.Y., Wei Z.F., Zeng C.L.
Format: Article
Language:English
Published: De Gruyter 2013-08-01
Series:High Temperature Materials and Processes
Subjects:
Online Access:https://doi.org/10.1515/htmp-2012-0150
Description
Summary:The low ambient tensile ductility and inadequate high temperature strength and creep resistance have limited the applications of intermetallic compound NiAl as a structure material at high temperatures. A small addition of Ag could increase the strength of NiAl. In this study, hot corrosion behavior of NiAl and NiAl-Ag containing 1 and 5%Ag (in weight percent), respectively, in molten (Na,K)2SO4 at 1173 K has been examined by thermogravimetry and physical analysis techniques. The experimental results indicated that the corrosion rates of NiAl and NiAl-Ag tended to increase with exposure time, accompanied with the formation of nodules. Fast localized corrosion is the typical feature of the corrosion of both NiAl and NiAl-Ag. The addition of Ag to NiAl accelerated its corrosion, with a higher corrosion rate observed for the 5%Ag addition. The two-phase microstructure of NiAl-Ag alloys accelerated the formation of nodules in the regions close to Ag phases.
ISSN:0334-6455
2191-0324