Article ID Journal Published Year Pages File Type
1640548 Transactions of Nonferrous Metals Society of China 2009 5 Pages PDF
Abstract

The NiAl alloys modified by reactive element(RE), dysprosium(Dy), were produced by arc melting. The microstructures of the modified alloys were investigated by field emission-scanning electron microscope(FE-SEM) equipped with energy dispersive spectroscope(EDS) and back scatter detector. Cyclic oxidation tests at 1 200 °C were conducted to assess the cyclic oxidation performance of the alloys. The Dy dopant prevents the surface rumpling of the oxide scale and the formation of cavities beneath the oxide scale. The pegs consisting of Dy-rich oxide inclusion core and an outer alumina sheath develop deeply in the alloy and improve the oxide scale adhesion. 0.05%–0.1% (molar fraction) Dy dramatically improves the cyclic oxidation resistance of the NiAl alloy. Too high concentration of Dy is deleterious because of the fast oxidation rate caused by severe internal oxidation.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys