Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10655644 | Intermetallics | 2005 | 7 Pages |
Abstract
The phase separation in the bcc phase of the Cu-Al-Ni system at 600-700 °C was investigated mainly by energy dispersion X-ray spectrometry (EDS) and differential scanning calorimetry (DSC). The compositions of the β1 (A2 or B2: Cu-rich), β2 (B2: NiAl-rich) and γ (γ-brass type) phases in equilibrium were determined. It was found that there is a β1+β2 miscibility gap in the β phase region as previously reported by Alexander. It was confirmed by means of high temperature in situ TEM observation that this miscibility gap consists of the B2+B2 phases but not the A2+B2 phases which is sometimes observed in many other Ni-Al and Co-Al base ternary bcc alloys. Thermodynamic calculation was performed which indicates that this characteristic feature suggests that the β1 (B2)+β2 (B2) miscibility gap is a part of a Cu-rich B2+NiAl-rich B2 miscibility gap island formed around the center of the composition triangle of the isothermal section. The phase separation in the β phase region and the stability of the ordered bcc aluminide are presented and discussed.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
R. Kainuma, X.J. Liu, I. Ohnuma, S.M. Hao, K. Ishida,